Why do we get sick in our holiday?

It’s the half term break and my Twitter feed is full of the usual story: teachers falling ill as their long awaited holiday starts. Is this just coincidence, people get sick all the time, so some will in their holiday, or is this a real effect? Are teachers actually more likely to become ill during the break from school? More importantly, if it is real, what can we do to prevent it?

Leisure Sickness

This term ‘leisure sickness’ has been coined by Dutch psychologist Ad Vingerhoets to describe the widespread anecdotal experience of becoming ill when we have a holiday. This isn’t a condition formally recognised in medicine but while there isn’t a straightforward mechanism to explain a link, we do know that illness can be induced by the effects of stress. It’s not the holiday itself that makes us ill, but the impact of stress in the run up to the holiday on our immune system.

Stress and Illness

In 1984 Janice Keicolt-Glaser demonstrated a link between exam-related stress in medical students and reduced immune function. Sheldon Cohen then demonstrated that people who reported stressful events in their life were more likely to become infected when intentionally exposed to cold viruses using nasal drops and were also more likely to develop clinical cold symptoms. Cohen’s research later showed that a range of chronic stressors (ie persisting for a month or more) increased our susceptibility to the common cold. The most significant stressors investigated in this study were those related to work.

So there is good evidence that chronic stress can impair immune function and increase susceptibility to infectious disease, but what about teaching? In a study of almost 300 US teachers, Dworkin et al (1990) found that illness increased proportionally to job stress. This supports the idea that workplace stress in schools contributes to teachers becoming ill.

Since a half-term is typically 6-8 weeks, workplace stress for teachers typically persists for over a month at a time, falling into Cohen’s definition of ‘chronic’. This is enough time for our immune system to become impaired do that we become more susceptible to infection. Add to this the incubation period for most cold viruses, and that’s the right timescale for teachers to begin coughing and sneezing just as their holiday starts!

What can we do?

The good news is that research indicates that there are several things we can do to reduce our chances of becoming ill.

1. Looking after our work-life balance during term-time rather than waiting for down-time in the holiday. We need to balance the demands of work with our health needs all the time. Easier said than done! Significant steps include being able to switch off from work and getting enough quality sleep.

2. Looking after our health. This includes making time for exercise, eating healthily, and avoiding things which have an adverse impact on our ability such as smoking. Cohen’s research shows that all these have a protective function. Initiatives like Teacher 5 a day can be a big help here.

3. Looking after each other. There is good research evidence that social support can provide protection against the effects of stress. If we all take some time to look out for each other, perhaps especially towards the end of term, we will all fare better. Those in leadership positions may have a special role to play: Dworkin’s study found that there was significantly less stress-related illness among teachers with a supportive School Principal.

You might also be interested in my posts on holidays and health which explore differences in resting heart rate during term-time and holidays.

Image: Pixabay

Things to look forward to in the 2019 Autumn Term

What happened to the Summer holiday? Half way through the first INSET day of the year, it may have already retreated to the distant recesses of your memory. Don’t despair; there is plenty to look forward to in the 2019 Autumn Term.

Autumn Term Top Ten

  1. Summer isn’t over! We’ll still have a few weeks of warmer days and longer evenings, so make the most of them before the nights draw in. British Summer Time ends when the clocks go back on 27th October.
  2. It’s a new school year! Remember when you were at school and got new exercise books? We wrote our names on the cover and opened the first new blank page full of possibilities. Your pupils will have that same feeling; how will you help them capture it and achieve great things? You can make their school year a great one!
  3. Take time to connect with nature. Look out for the signs that summer is turning into autumn. Which plants are coming into bloom now, rather than in spring or summer? Which fruits are ripening, which leaves are changing colour first? Which animals do you notice? Take note of these small changes and you’ll soon see that no two days are alike.
  4. The annual Macmillan Coffee Morning is now a fundraising fixture in many schools. Something to do with the cake perhaps? This year it’s on 27th September. You can sign up and get more information and a fundraising kit here: World’s Biggest Coffee Morning 2019
  5. In the UK, October is Black History Month, which honours and celebrates the contribution Black Britons have made to our vibrant and diverse society. You can find out more and order a school resource pack from blackhistorymonth.org. There are also regional listings so you can look for events local to you.
  6. There are plenty of other key dates, holidays and festivals to mark during the Autumn term. The Jewish holiday of Rosh Hashana is on 30th September and Yom Kippur falls on 9th October. Diwali (Deepwali), the Hindu, Sikh and Jain Festival of Lights, is on 27th October. Halloween (or All Hallows’ Eve) is on 31st October, preceding the Christian feasts of All Saints’ Day the next day and All Souls’ Day on 2nd November. This year, Remembrance Sunday is on 10th November and many schools will mark Armistice Day at 11am on the Monday. Scotland celebrates St Andrew’s Day on Saturday 30th November, with the bank holiday in Scotland on Monday 2nd December. The first Sunday of Advent is shortly after on 1st December, bringing us to the lead-up to Christmas. Hanukkah begins on the 23rd of December and ends on the 30th.
  7. There are many National and international Awareness events that schools may wish to get involved with in the Autumn term. As well as being Black History Month, October is also the month of the annual Big Draw with artistic event taking place around the country. Get set for a busy day on Monday 7th October which is Jeans for Genes Day, National Poetry Day, AND World Smile Day! Many schools will be fundraising for the annual BBC Children in Need appeal, which this year is on Friday 18th November, and will be getting involved with Anti-Bullying Week, 11-15th November. The theme this year is ‘Change Starts With Us’. You can get more information and resources from the Anti-bullying Alliance.
  8. When the nights do draw in, and the weather gets colder, what better way to celebrate than bonfires and fireworks on Guy Fawkes Night, 5th November? Gunpowder, treason and, with any luck, toffee apples. Worth a reminder about firework safety.
  9. Some of the best bits of school happen in the Autumn term and will be upon us before we know it: if I were you, I’d check your Christmas jumper for moth holes and start planning the school Nativity Play now.
  10. At the end of this term, the Christmas holiday and New Year!

So, what are you looking forward to this Autumn term? Are there any dates I’ve missed out? Why not share with a comment?

Looking for some more inspiration for assemblies? Have a look at these educational quotes for Monday morning motivation.

Festival dates from timeanddate.com

Image: Rodger Caseby

Things to look forward to in the 2019 Summer term

The summer holiday may seem a long way off, and exams may loom for many, but there’s also plenty to look forward to in the Summer Term.

Summer Term Top Ten

    Enjoyed the bank holiday weekend? There’s another one soon on Monday 6th May!
    Easter isn’t over! It isn’t just one chocolate-laden bank holiday weekend, but the greatest season of the Christian tradition, running until June this year. In the Orthodox calendar, Easter Monday is on 28th April.
    Easter is traditionally a time for embracing new life and new beginnings. Perhaps it’s a good time to consider our own professional practice – are there any aspects that we might revitalise or new things we could try?
    There’s no more waking up before sunrise and coming home in darkness. Longer (hopefully) sunlit days help lift our mood, so make some time to go outside each day. Even when it’s overcast, natural sunlight will do you good.
    While you’re out and about, take some time to connect with nature. Look out for the signs that spring is turning into summer. Which plants are coming into bloom? Which birds, bees and butterflies do you notice? Take note of these small changes and you’ll soon see that no two days are alike. You can even use the iRecord app to add your nature sightings to the National database
    A couple of international dates recognising our dependence on our environment fall within the Summer term. The UN World Environment Day is on 5th June and Oceans Day is on 8th June. With young people becoming increasingly concerned about climate change, perhaps that week could be a focus for environmental awareness and action at school?
    There are plenty of key dates, holidays and festivals during the Summer term. These include St George’s Day on 23rd April and the last day of Passover on 27th April. Yom HaShoah (Holocaust Remembrance Day) is on 2nd May this year and Ramadan starts on Monday 6th May, running until Eid I’ll Fitr on 4thJune. 6th May is also 75th anniversary of the D-day landings in Normandy. The Spring Bank Holiday is on Monday 27th May. 9th June is both the Christian Pentecost and Jewish Shavuot. In the UK, Fathers’ Day is on 16th June, and the Summer Solstice is on 21 June. 22nd June is Windrush Day. Initiated in 2018, this day marks the anniversary of the arrival of the Empire Windrush at Tilbury docks in 1948 and celebrates the British Caribbean community.
    You may have pupils taking exams this term. While I’m proud of my qualifications, I’m also very pleased that the ticking clock and wobbly exam desk are well behind me! We all survived the process, so now we get to use our experience to help our students to succeed as well. I’ve written about tackling exam stress here. The article also contains links to useful websites offering further advice to students and parent & carers.
    Some of the most memorable aspects of school life happen in the Summer term: school trips, outdoor education, Summer concerts and productions, PTA barbecues, sports days, proms, end of year awards. Some schools have activities weeks, others move to their new timetables before the holiday. These and more enrich the curriculum and help build communities.
    At the end of this term… Summer holiday!

So, what are you looking forward to this Summer term? Are there any dates I’ve missed out? Why not share them with a comment?

Festival dates from timeanddate.com

Image: Rodger Caseby

Does music help or hinder revision?

In the run up to the Summer exam season, when even the most laid-back students begin to think that some revision might be a good idea, teachers are likely to be asked if music is a help or a hindrance.

The current crop of GCSE and A Level students are probably too young for their parents to have been devotees of the ‘Mozart Effect’; Those claims made in the 1990s have long been debunked and were a mixture of overgeneralisation from Frances Rauscher’s original research on the effect of a particular Mozart piano sonata on a specific type of spatial learning, popularisation by the media, and marketing of Mozart recordings. The results could not be reliably replicated and the wider claims for an effect on IQ were never made in the original research.

So, listening to Mozart won’t make us smarter, but there is research showing that music can raise task performance. The most likely reason for this is that music raises the arousal level of participants, increasing their performance. An example is a study by Shellenberg et al (2007) who reported improved cognitive and creative task performance in children and adults after listening to music (see the abstract here).

On the other hand, some research has shown that listening to music is counter-productive to learning. Jones et al (2000) found that the variability in the auditory input was the key factor. Alley & Greene (2008) found that vocal music impaired performance (as did listening to speech) but not instrumental music. These effects happen because processing an additional, auditory, channel is a distraction to cognitive processes which require us to use our working memory capacity to hold and process items of information.

Why then does some research point towards a beneficial effect, and other studies indicate that music impairs performance? The answer may lie in these areas:

1) individual differences between participants.

Most studies report summary results: the overall effect among all the participants, but this may obscure differences in individual responses. There is some evidence that personality traits play a role in this, with negative effects on introverted participants but not extroverts (Dobbs, Furnham & McClelland, 2011), possibly because of differences in optimal arousal levels between these two groups.

In a recent study, Researchers looked at how prone students were to boredom (Gonzalez, M. F., & Aiello, J. R. (2019), Advance online publication). They found that more boredom-prone individuals who tended to seek distraction (and so perhaps are most likely to play music while working) were the most distracted by background music. This is possibly because they tended to focus more on the music than the set tasks, whereas for less boredom-prone individuals the music provided just enough stimulation to prevent them becoming bored with the tasks.

2) Differences between the type of tasks studied. Crucially are they like revising for an exam?

Often research features simple, easily replicable tasks. Exam revision in contrast is complicated, involving not only recall of information, but also the formation of complex associations, the understanding of abstract models and application of all this to novel questions. Research studies such as that by Alley & Greene (2008) indicate that the more complex the task, and the greater the requirement for abstract reasoning, the greater the reduction in performance caused by music. It may be that the harder the learning gets, the more we should avoid distractions such as music. In a study specifically looking at revision, Perham & Currie (2014) found that music with lyrics impaired learning (irrespective of whether the students liked the songs or not), but there was no significant difference between performance when listening to instrumental music or in quiet conditions.

3) What is the type of music?

Many of the research studies mentioned featured instrumental music. That probably isn’t the first choice for most students but it may be the option that doesn’t interfere with cognitive processes. Perham and Currie (2014) reported that instrumental music did not impair revision significantly and Hallam, Price and Katsarou (2002) found that 10-12 year-old pupils actually performed better at a memory task when listening to a pleasant melodic piece than no music and much worse when listening to to an unpleasant aggressive piece.

4) What is the alternative to music?

Typically in a research study the control will be silence, but what will conditions be like where a student is revising? Hopefully they will have a quiet space to work in but this is not always the case. Schlittmeier et al (2012) collected data on the impact of 40 different sounds on working memory task performance. These included background speech, traffic noise, music and duck quacks. All these impaired performance, the greatest interference being produced by background speech. For those who don’t have a quiet study space and need away of blocking out such distracting sounds, listening to music over headphones could be beneficial.

How to decide?

Overall, most of the research indicates that while pleasant instrumental music doesn’t impair cognitive performance for most people, it won’t enhance it either. So the safer option would be not to play music when revising. In some circumstances, however it could be helpful. Answering these questions will help students decide:

1) Is there a lot of background noise where I have to revise?

2) Do I prefer to work in a lively environment with a group, as opposed to working quietly on my own or with a good friend?

3) Do I find it easy to concentrate on a single task, such as revising one topic?

4) Is the music I want to listen to instrumental, rather than songs with lyrics?

If the answer to these questions is ‘yes’, then you can probably listen to music quietly with no harmful effects on your work (and if you need to cut out distracting ambient noise it will be helpful). Otherwise, it’s probably best to save the music for the times between revision sessions.

References

Alley, T. R., & Greene, M. E. (2008). The relative and perceived impact of irrelevant speech, vocal music and non-vocal music on working memory. Current Psychology, 27, 277-289.

Dobbs, S., Furnham, A., & McClelland, A. (2011). The effect of background music and noise on the cognitive test performance of introverts and extraverts. Applied Cognitive Psychology, 25, 307-313.

Gonzalez, M. F., & Aiello, J. R. (2019). More than meets the ear: Investigating how music affects cognitive task performance. Journal of Experimental Psychology: Applied. Advance online publication.

Hallam, S., Price, J., & Katsarou, G. (2002). The effects of background music on primary school pupils’ task performance. Educational Studies, 28, 111-122.

Jones, D. M., Alford, D., Macken, W. J., Banbury, S. P., & Tremblay, S. (2000). Interference from degraded auditory stimuli: linear effects of changing-state in the irrelevant sequence. Journal of the Acoustical Society of America, 108, 1082-1088.

Perham, N., & Currie, H. (2014). Does listening to preferred music improve reading comprehension performance? Applied Cognitive Psychology, 28(2), 279-284.

Rauscher, F.H., Shaw, G.L., & Ky, K.N. (1993). Music and spatial task performance. Nature, 365, 611.

Schellenberg, E. G., Nakata, T., Hunter, P. G., & Tamoto, S. (2007). Exposure to music and cognitive performance: Tests of children and adults. Psychology of Music, 35, 5-19.

Schlittmeier, S.J., Weißgerber, T., Kerber, S., Fastl, H. & Hellbruck, J. (2012). Algorithmic modeling of the irrelevant sound effect (ISE) by the hearing sensation fluctuation strength. Atten Percept Psychophys 74: 194. 

Image: Pixabay

The Student Strike for Climate

On Friday thousands of students across the UK left their lessons to take part in demonstrations demanding action to tackle climate change.

I currently teach part time in Oxfordshire and the protest in Oxford had one of the highest turnouts, with the media reporting an estimated 2,000 young people rallying to the protest in the city centre. I’m not in school on Fridays, it’s one of the days I work in the education team at the Bodleian Libraries, so I went along in my lunch break to see how the demonstration was going.

In common, I suspect, with many teachers, I felt some internal conflict over this student strike for climate. On the one hand I find it extremely encouraging, indeed inspiring, that young people should be taking a leading role in this crucial issue; on the other there are, of course, difficulties in condoning time out of school and missed lessons, especially in the run-up to GCSE and A Level exams. How many students would be genuinely concerned and actively engaged in tackling climate change and how many just taking an easy opportunity to bunk off on a Friday afternoon?

The headteacher of my school made a very reasoned response when approached by students about the strike; not authorising their absence but celebrating their desire to speak out and prompting them to think beyond attendance at an event arranged for them, to organising practical action in their own time. He commented on the strike in the newsletter Take Me Home and also included the Students’ eloquent letter to their local MP.

I was very impressed by the demonstration itself. Before reaching the venue in Oxford’s Bonn Square I encountered a march along Cornmarket (pictured above), with banners flying and some well-coordinated chants. This got the message across in a forceful but good-humoured way and was certainly getting a lot of interest from the public.

The main protest in Bonn Square was still in full voice, with impassioned speeches, music, chanted slogans and banners. It was the latter that really impressed me. Although there were a few of the inevitable printed placards from Socialist Worker (say what you like about Trotskyists, they know how to run a printing press), most banners were individual and imaginative hand-made, labours of love. My particular favourites were “Think or Swim” accompanied by a picture of Westminster flooded by rising sea levels, “The Climate is Changing, Why Aren’t We?” and, with a nod to the Green Party, “We’ll listen to UCAS when you listen to LUCAS”. I do hope the creators find a way to work their banners into their art portfolios.

The vast majority of people were actively engaged. Yes, there were a few kids in town who were out of school but didn’t seem to be connecting with events in any way, but nothing like the numbers of opportunists some commentators had predicted.

In education we tend to be judged on outcomes. I can’t think of a better outcome from schools’ work on citizenship and Fundamental British Values (not to mention the science input on the greenhouse effect and climate change) than that students stand up for what they believe in and attempt to effect change by engaging in the democratic processes of a free society, including petitioning elected representatives and making peaceful public protest. The alternative is for the youth of our nation to be disengaged and at best apathetic, at worst disillusioned and disconnected from the rest of society.

Friday’s protest made a point. Maybe the protest could have been at the weekend, but I think we all know that would have gained less coverage and prompted less debate. Let’s hope we can all now move from protest to effective action because our young people are right: whatever our age, the climate clock is ticking and there is no planet b.

Adventures in Whole Class Feedback: Planning for Feedback

I have been interested in the claims made for whole class feedback for some while, but have had some reservations. I have always seen formative assessment as a central element of teaching and learning, and providing written (as well as verbal) feedback as crucial to helping children understand what they have done well and what they need to do to improve further. I also quite like marking and enjoy both the immediate reaction of children to seeing their hard work appreciated, and their longer term journey of progress over time.

Nevertheless, while I may like marking, I don’t always like the time it takes. As I write the same comment on the fourteenth piece of work from a class, I find myself thinking that this probably wasn’t the best use of my time. As Anthony Radice wrote in this post Whole Class Feedback: A Winner All Round, it’s important for teachers to consider what else we could be doing with the time we spend in close marking like this, and whether other activities, such as planning or creating resources, might be more useful in helping pupils make progress.

With all this in mind, I agreed with my line manager that development of whole class feedback would be an objective for my performance review this year. I’ll be developing my practice in class and feeding back to the departmental team.

When and what to mark

I have decided to focus on year 8 as I have three mixed ability computing classes in this year group.

There are several types of task that these classes do:

  1. Work in class which will be directed to an element of a unit, for example editing sound files in a unit on podcasts, or the use of subroutines in a unit on algorithms.
  2. Half-termly Homework. In computing pupils choose a task for each half of each term. This is an individual project they work on for several weeks. Examples include designing a website on a theme, or designing a revision resource for a topic. Pupils work on different tasks.
  3. Discrete homework. These are shorter homework tasks, taking a few minutes, for example reinforcing key vocabulary, or a quiz on PEGI game ratings. They are set one lesson for completion by the next. The tasks may be differentiated, but everyone is doing the same thing.

I think some of this work lends itself more to whole class feedback. In class we are usually all working towards the same goals. It’s easy for me to pick up on good examples and also to spot errors or misconceptions. In class it makes sense to give verbal feedback to the class (as well as taking opportunities to talk to individuals. The written feedback is for myself: picking up on what happens in the lesson to better inform my teaching.

Pupils put a lot of work into the half-termly homework and I think they deserve some individual feedback from me. What I’m aiming to work on is making that feedback truly individual. Rather than repeating comments on common themes, though, I intend to note these and address them as feedback to the class.

The discrete homework tasks are usually self-marking tasks such as quizzes, so my focus is usually in picking up on what the scores mean, such as a misunderstanding of a particular concept. Often I will revisit this on teaching, rather than give specific feedback on the homework, but I’ll see if doing so is more effective.

So, that sets the scene for what I plan to do:

  • Continue to use verbal in-lesson feedback as I do already, but keep better track myself of how it informs my teaching.
  • Restrict individual feedback for the truly individual elements of homework projects and add whole class feedback of common learning points.
  • Give whole class feedback a try for discrete tasks, where previously I might have just revisited the learning in the course of a lesson.

I’ll make sure to feedback how We get on!

Image: publicdomainpictures.net

Learning and long-term memory

A while ago I wrote a post about how we can structure learning to make the most of pupils’ working memory capacity. A recent conversation on Twitter prompted me to write this post on how an understanding of long-term memory can inform our teaching.

Short-term and long term memory

Both these terms are used in everyday English, but psychologists tend to use them in a specific way. Our short-term memory is thought to have a limited capacity and duration, holding a few items for a short period of time, usually just a few seconds. In contrast, our long-term memory has a huge capacity and stored memories can last a lifetime.

Types of long-term memory

Our common experience is that we have different types of memory. We may, for example, have a memory of a childhood birthday which allows us to recall sights, sounds, smells, tastes and emotions. This seems quite distinct from the memory of what the word ‘elephant’ means, or what the capital of France is. Psychologists have classified these memories into three types (although further distinctions are possible):

Semantic memory – memories of facts and figures, for example knowing what a bicycle is, being able to name the parts of a bike and explain their function.

Procedural memory – memories of how to perform an operation, for example being able to ride a bike.

Episodic memory – memories of specific events and personal experiences, for example the first time you rode a bike unaided. Episodic memories contain not only the specific details of the event, but the context and emotions of the experience.

Evidence that these types of memory are associated with distinct areas of the brain comes from studies of brain-injured patients, and from brain imaging. Some patients who have sustained brain injuries retain abilities in one area but not others. An example is the much-studied amnesiac HM who could form new procedural memories, such as the skill of mirror-drawing, but not semantic or episodic ones (Corkin, 2002). While memory function can be highly distributed in the brain, procedural memories are associated with activity in the cerebellum and motor cortex, episodic memories are associated with activity in the hippocampus and semantic memories with activity in the temporal lobe.

Long-term memory and learning

The two are inescapably related and we could define learning as a change in long term memory. This happens when information is transferred from short-term memory into long-term memory and incorporated with the information already held there. To make use of this information, we must retrieve the information from long-term memory.

Teachers can use an understanding of these processes to improve the efficiency of learning:

    Introduce new information gradually Information must be processed to be effectively incorporated into memory. Introducing new information too rapidly will not only reduce the proportion that is retained, but prevent it being effectively integrated with prior learning. This risks creating an incomplete understanding of concepts and a limited ability to apply knowledge to problem solving because of gaps in our understanding. This will of course vary from pupil to pupil, so it’s important to build in assessment that will inform the pace of future planning. Resist the temptation to plough through content at the expense of learning.
    Contextualise new information In everyday life we find that it is easier to remember information that has meaning. It’s easier to remember a friend’s phone number or birthday than a random string of digits with no context. Research supports this idea. Our consolidation of information into long-term memory and subsequent ability to retrieve it is improved when that information is presented in context, allowing us to readily make connections between new and existing information.
    Provide time and tools for practice To effectively consolidate new memories, connections must be made with existing knowledge. We need to give students enough time to do this. For semantic memories, this includes opportunities to explore new knowledge and concepts by applying them to novel situations and problems. For procedural memories, opportunities should be given to practise operations and procedures, and to use any equipment or materials needed to do this.
    Testing works better than reviewing Students May view revision as literally that, re-reading information that they have previously learned. Research shows that repeatedly attempting to retrieve information from long-term memory is a much more effective strategy. Quizzes, tests, and opportunities for self-testing will help students learn new information much more effective than reviewing content. For semantic memory, recall quizzes and tasks requiring the correct use of information, including past exam questions, will help. For procedural memory, opportunities to do things, and recount how procedures work will be beneficial.

Practical examples

Some practical examples of these strategies include:

  • Quizzes at the start of a lesson about the content covered previously
  • Checkpoints in the lesson to assess understanding of information
  • Taking time to look at the ‘big picture’, placing new learning in the concept of overarching principles or concepts of the subject
  • Drawing diagrams that connect new information with existing knowledge, within and across topics / subjects
  • Practice at applying new knowledge to solve problems, either in class or as homework, to consolidate semantic memories and improve their recall
  • Practice of new routines, operations and skills to achieve goals or solve problems to consolidate procedural memories and improve aptitude
  • Explaining new learning to others, either verbally or in writing
  • Writing test questions and answers, rather than just reviewing knowledge.

You may be interested in other posts on Psychology and education:Exams and stress – Exams: use the motivation, lose the stress

Academic success and exercise – Want to improve academic performance? Look to PE

Working memory and learning – Making the most of working memory capacity