Associate Professor • Department of Psychology • UCSC • Santa Cruz, CA • 95060 • 831.459.5767 • Room 412, Social Sciences 2

Current Research

If you are interested in any of these projects, please e-mail me for further information.

Synaesthesia: One Phenomenon or Several?

In people with synaesthesia, certain sensory stimuli evoke other sensory impressions. For example, musical notes may evoke shapes, or the letters of the alphabet may evoke colors. Also of an interest is a phenomenon, sometimes grouped with synaesthesia, of seeing familiar sequences like the counting numbers laid out in some kind of spatial arrangement. But are these all the same underlying phenomenon? Akalka Barath and I have demonstrated that they are not. Synaesthesia for qualities (e.g. music -> shapes) does not correlate with picturing sequences in space. However, both of these do correlate with sequences evoking qualities (e.g. alphabet -> colors). We propose that the latter is a hybrid phenomenon that is particularly likely in people who happen to have both of the first two.

Synaesthesia and Personality Characteristics

Previous reports in the literature indicate that people with synaesthesia may be more likely than others to be on the autism spectrum, and more likely to have characteristics of schizotypy. However, these conclusions were based on self-referred synaesthetes, which is known to introduce biases into the sample. Akalka Barath and I have shown that synaesthesia in fact does not correlate with autism spectrum, and we are in the process of testing the schizotypy claim.

Synaesthesia Across Languages

Akalka Barath has found that Spanish-English bilinguals generally have the same color associations for days of the week and months of the year in both languages, whether the words sound similar in the two languages (febrero - February) or different (lunes - Monday). Also, interestingly, some bilinguals report having color associates for English but not for Spanish. Given the demographic trends of our population here in California, we suspect this indicates a role of early schooling in the development of these associations, a hypothesis that we are currently pursuing.

The Cognitive Benefits of Movement Reduction: "Marking" in Dance Rehearsal

Ballet dancers and others (gymnasts, etc.) frequently "mark" a sequence of moves during rehearsal, by performing a highly reduced version. Among ballet dancers there is a belief that marking is only useful for saving energy, but an alternative hypothesis is that reducing movement actually reduces cognitive load, and can facilitate learning of the performance. Edward Warburton of the UCSC Theater Arts department and I have found that this is indeed the case -- dancers who spend part of their rehearsal time marking do better in final performance than dancers who only rehearse "full out." Followup experiments on movement reduction in other contexts are planned.

"Dancing" to a Beat in Non-Human Animals

Previous authors have argued that only vocal-learning species, such as Youtube celebrity Snowball the cockatoo, can learn to entrain to a rhythmic stimulus. Peter Cook has led a team that trained a California sea lion -- a vocally inflexible species -- to bob her head in time to music. This disproves the vocal learning hypothesis and opens a range of further questions about the ability of animals to entrain.

Exploring the SNARC Effect

In the SNARC effect, subjects respond faster to large numbers on the right side of space and small numbers on the left side of space, reflecting the standard number line. This phenomenon clearly has similarities to the spatialized-sequence form of synaesthesia describe above. In this project we will be exploring aspects of the SNARC effect, including whether other judgements of magnitude (e.g. size of animals) show the same effect, and whether people with self-reported spatial synaesthesia show stronger or different SNARC effects.

Acquistitiveness as Species-Specific Human Characteristic that Contributed to Evolution

Sara Green, Akalka Barath, Charlotte Massey, Matthea Moura and I are preparing a paper in which we argue for a fundamental role of acquisitiveness in human cognition, which played a role in driving the evolution of other cognitive characteristics such as future planning, heirarchical organization, and observational learning.

Rethinking Working Memory

This theoretical paper in progress argues that conceiving of working memory as either a system or multiple systems, with a dedicated status in the brain, cannot hold up against the avalanche of "working memories" that are being discovered. Instead, I argue that working memory is a strategy -- in particular, the strategic recruitment of sensory and motor resources that usually serve other purposes. I further argue that the role of motor representations in working memory depends upon the ability to flexibly imitate perceived stimuli, and that this revolutionized working memory in the human case.

Website Design by Daniel Leavitt
Website Logo 'The Thinker' by Gabriel Leonoudakis