SCLM Symposium Schedule

The Eleventh Annual

Southern California Learning and Memory Symposium

June 6^th, 2012

Leichtag Auditorium

University of California, San Diego

8:15 Continental breakfast

8:55 Welcome and Opening Remarks

Session 1

9:00    Larry Squire: The hippocampus, memory and spatial cognition.

9:30    John Wixted: Recollection and familiarity in the hippocampus

10:00  Rosie Cowell: Paradoxical False Recognition: New objects look old in a model of amnesia

Session 2

11:00  Alcino Silva: Molecular and cellular mechanisms of memory allocation

11:30  Sarah Mednick: Reaching beyond the limits of memory: Experimenting with learning, sleep, and drugs.

12:00  Mark Mayford: Genetic Control of Memory Circuits

12:30 Lunch

Session 3

2:00    Barbara Knowlton: The role of medial temporal lobe subregions in declarative memory

2:30    Sarah Bottjer: Singing in the brain: cellular and circuit mechanisms of vocal learning

3:00    Xin Jin: Basal ganglia and action learning in mice

Session 4

4:00    Jill Leutgeb: A neuronal code for extended time in the hippocampus

4:30    Antonio Rangel: What is the role of learning in simple and complex choice?

5:00    Tom Albright: Gaining Sensory Expertise

Sponsored by the Departments of Psychology, Neurosciences, Cognitive Science and the Kavli Institute for Brain and Mind

CNS Seminar: Jesse Rissman

May 29th

Jesse Rissman
Dept of Psychology
UCLA
http://rissmanlab.psych.ucla.edu

Decoding real-world autobiographical retrieval experiences from fMRI activity patterns

Throughout our day-to-day lives, we are constantly faced with the task of evaluating how elements of our present environment relate to our past experiences. The ability to do so is thought to depend on a distributed network of frontoparietal and medial temporal lobe regions, with the particular pattern of neural activation within and across these regions closely linked to one’s subjective feeling of familiarity for a given retrieval cue and/or the recollection of associated episodic details. We have recently shown that it is possible to reliably decode such aspects of observer’s mnemonic retrieval experience based on the distributed fMRI activity patterns elicited by individual retrieval cues (Rissman, Greely, & Wagner, 2010). However, as with many memory experiments, the memories assessed in that study were all for a single class of stimuli (faces) studied in a laboratory setting immediately prior to scanning. In the present talk, I will describe an fMRI experiment designed to gain ecological validity by characterizing the brain activation profiles associated with the retrieval of contextually rich real-world autobiographical memories. By providing our participants with wearable digital camera devices that automatically captured tens of thousands of color photographs from their day-to-day lives, we had the unique opportunity to later scan participants while they viewed photos from their own life events, interspersed with photos captured by the cameras of other participants. Whole-brain multi-voxel pattern analysis (MVPA) revealed that correctly recognized events could be distinguished from correctly rejected novel events with remarkable accuracy, and mnemonic decoding performance was stable across events captured throughout the 3-week camera-wearing period. Furthermore, MVPA classifiers could be trained to reliably differentiate recollection from familiarity, as well as to determine the strength of recollection, familiarity, or novelty that a participant experienced on a given trial. Classification importance maps revealed dissociable neural signatures of these mnemonic states, with activity patterns in the hippocampus, medial prefrontal cortex, and ventral posterior parietal cortex being particularly diagnostic of event recollection. I will discuss the implications of these results for neuroscientific accounts of episodic retrieval and comment on the potential forensic use of fMRI as a tool for probing experiential knowledge.

CNS Seminar May 22nd: Isabel Gauthier from Vanderbilt University

Perceptual expertise and selectivity for faces in the ventral temporal cortex

More than twelve years ago, my colleagues and I found evidence of selective responses to cars in the fusiform face area in the ventral temporal cortex of people with expertise recognizing cars. This has been a central piece of evidence for the claim that the selectivity in the FFA for faces develops as a result of our experience with faces. Since then, high-resolution fmri (HR-fMRI) and fMRI-guided neurophysiology in the monkey have suggested no reliable selectivity for non-face objects in the FFA or its monkey homologue. One can therefore ask whether expertise effects may simply be due to spatial blurring from non face-selective voxels. Using HR-fMRI at 7Tesla, we found evidence for robust expertise effects within the most face-selective voxels at the peak of face-selectivity. These effects were spatially contiguous with face responses, and the selectivity of these voxels for face relative to other objects actually decreased as a function of expertise in the most anterior part of the FFA (FFA-2). I will also report on other work at 7T and 3T that reveal how this part of the FFA shows the most robust expertise effects when a task becomes more attentionally demanding, and that expertise effects for non-face objects are robust in FFA in conditions of inattention but are reduced when presented among objects for which they compete for perceptual resources. In sum, I will argue that face-selectivity in VTC is best studied as a instance of perceptual expertise, a framework that gives us a handle on specialization for different categories more generally across the visual system.

CNS Seminar: Justin Kiggins & Tristan Shuman

May 15th

Justin Kiggins
Neurosciences Graduate Program
UC San Diego

Representations of learned sequence statistics in the avian auditory forebrain
Abstract. Sensory events unfold in time, and the relative serial position of events is crucial in speech and language perception. European starlings readily learn to recognize other starlings by their songs and rely in part on the sequential patterning of motifs to do so. To explore the neural representations of learned acoustic sequences, we developed an operant conditioning task in which the only relevant information available is the statistics of transitions between motifs. We find that sequence information can both suppress and facilitate responses in the songbird auditory forebrain, and cannot be explained by a simple linear summation of the two motifs in a transition. Further analyses suggest that responses to motif transitions reflect the statistics of prior behavioral exposure


Tristan Shuman
Dept of Psychology
UC San Diego

Localizing the neural correlate of cocaine seeking behavior
Abstract. Cocaine administration induces many changes in behavior that are likely to underlie addiction. We used a transgenic mouse to label cells that are active at both the initial drug exposure as well as during drug seeking at a later time.  We found that cells in the dorsal striatum were more likely to be activated at both time points compared to control animals indicating that the dorsal striatum may be the region where drug seeking behavior is initiated.

CNS Seminar. Karen Dobkins

May 8th

Karen Dobkins
Dept of Psychology
UC San Diego

Intermingling of Sensory Representations over the Course of Development

Abstract. Early infancy is characterized by a period of exuberant neural connectivity followed by a retraction and reweighting of connections over the course of development.  It has been proposed that this connectivity may produce a perceptual intermingling of the senses in infants that is unlike that experienced by typical adults.  And, a lack of pruning of these exuberant connections during development is thought to explain the rare condition of “synesthesia” in about 2% of adults, wherein one sense involuntarily evokes an additional arbitrary sensation.  We have been studying the perceptual consequences of neuronal intermingling in young infants and adults with “grapheme-color” synesthesia, wherein specific letters or numbers evoke idiosyncratic, largely individualized sensations of specific colors.  Our results in typically developing infants (2 to 4 months) are consistent with them making strong associations between color and shapes (a precursor to graphemes), as well as between color and motion, which are significantly greater than the associations experienced by typical adults.   Such findings – which suggest that all young infants experience synesthesia, provide a perceptual consequence of the exuberant neural connections seen in the infant brain.  This talk will also present data from studies in adult grapheme-color synesthetes. Here, our results suggest that the exuberant intermingling of color and grapheme representations in synesthetes comes at the expense of connections between color and other aspects of vision, specifically, motion.  We also find that adult grapheme-color synesthetes discriminate colors better than controls, which we suggest may arise from “bi-directionality”, whereby colors elicit an additional experience of graphemes that aid in color discrimination. This heightened color sensitivity could help explain why synesthesia has survived in evolution.