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Day 5 10:01 Roee Gilron, Brandeis; First Impressions. What determines if we remember a first impression? One’s state? How one diagnoses the person? Behavioral studies have focused on a single action and a single actor (Uleman 2008). Imaging studies (Mitchell 2006, Harvey 2007, Schiller 2009) used multiple actions from a single actor. Is there a social memory system? The HP doesn’t seem to be involved; the dmPFC seems to be. This study asked participants either about the targets’ impressions or semantic information, given pos/neg (diagnostic) or neutral sentences. Diagnostic sentenced targets were remembered better. Brain activity was remembered in encoding stage based on which targets were remembered successfully. The dmPFC and aCC emerged as significantly activated regions. The left inferior frontal love was found larger for semantic memory than implicit memory. The HP was more active in neutral memory rather than diagnostic memory. ACC involved in incidental impression formation, but not intentional impression formation. HP engagement supports incidental but not intentional impression formation. Donna Bridge, Northwestern; social; power mediates math. There is a neural basis of social hierarchy (Zink 2008, March 2009, Freeman 2009, Chiao 2009). Social power is defined as the ability to control outcomes of situations, particularly allocation of resources. Social power can be primed by asking to write an essay about when they encountered social power. High power reduces susceptibility to interference (Smith 2008) and enhances global attentional processing (Guinote 2006). Low power emphasizes analytic processing strategy, focusing on details; and it reduces their ability to filter extraneous information. (It may come from a fear that others are manipiulating them.) Abstract and concrete math skills can be dissociated, and abstract math predicts math achievement. The two conditions in this experiment involved exact calculation (3+4= 6 or 7?) or approximate calculation (3+4= 6 or 9?). Exact involves rote memory retrieval, learning does not generalize, and involves left IFG. How does social power affect neural mechanisms underlying math mechanism? Power may distinguish strategies used. High power may rely more on IPS; low power may use lIFG. Half of the participants were primed to high-power, the other half low. Surveys on mood, ACT, math ability, etc. showed no differences. High-power participants were better at approximate, approaching significance. Exact recruited lIFG and angular gyrus. Approximate exhibited IPS and SPL. Low-power group recruited lIFG more for approximate than exact. Low-power participants recruited dACC more for approximate calculations relative to exact. Marina Pavlova, Tübingen, Neuromagnetic cortical correlates to social communication. Right temporal has been described as “social brain area.” And yet, preschoolers consistently describe cartoon of abstract shapes as social interaction. ASDers are impaired on this social interaction, providing only physical interpretations. ASDers have reduced connectivity to STS, reduced structural STS. In these activities as well as wireframe animations, rSTS and right fusiform face area are activated. Gamma activity has been shown to underlie intact brain communication (Womelsdorf 2007), particularly social communication. Exzperiment used shapes “caressing” and “kissing” (as commonly described by viewers). rSTS and right PTJ were activated, unsurprisingly. The study also looked at gender differences. Are these differences natural or sociocultural? Females are generally better than boys, except for faces such as anger. There were no gender differences for region activations across averages. In left medial prefrontal area, females showed a peak much earlier than in males. This area is involved in perceptual decision making. Females anticipate social interaction, whereas males have to pay high prices for their errors. Future studies may wish to study these differences in ASDs. 12:42 Turns out, the NAcc core is involved in acting on reward-predicting cues, and the shell is involved in not acting on non-predictive cues. The neuronal firing activities of the two regions looks the same, although the firing of individual neurons on the core can be predicted by the reward-predictor, whereas those in the shell merely act due to lever pressing. The OFC is involved in mediating reward, and delaying rewards for the longterm. Animals tend to prefer short-term, immediate rewards over long-term ones. The preference for long-term rewards is mediated by the OFC. Deactivating the prelimbic vmPFC with muscimol and balcofen does not decrease food seeking in hungry rats under a FR1 schedule, but it does under a progressive ratio schedule. 13:32 Executive control nanosymposia. I’ve arrived late, so my notes on the earliest few presentations are nonexistent. Keliris GA, V1 in executive control. Binocular rivalry is interesting because input remains the same but perception fluctuates: Two images are presented, one in each eye; subjects perceive the image in the center of the field as varying. V1 is of interest because it is the cornerstone of the visual system and is the first stage of binocular interaction; that is, the first place where information from the two regions interacts. Previous studies (Logotbetis, 1998) suggests that the competition is happening in the temporal lobe, but primate (incl. humans) implicates activity in V1 activity in this process, and fMRI studies implicating V1 in visual field dominance. Is this competition between low-level eye channels, or higher stimulus representations? They used the technique of binocular flash suppression, which involves an animal viewing two screens, with both eyes centered on the center of their respective screens, with competingly oriented stimuli. Single cell studies in primates showed 20% of neurons showing perceptual modulations in the twostimulus conditions. Gamma wave activity mimics the behavior of single cells. Cells were then categorized according to which orientation of stimuli they prefer, and which ocularity (left/right eye) they prefer. All cells were evenly distributed, concentrated most highly around the origin; same goes for those cells that showed visual disturbances. Cells were categorized according to whether they’re modulated by ocularity or orientation, or both. The activity of these cells can predict perceived orientation and eye-of-origin according to their sensory preferences. Shi-Chieh Lin, Duke/NIA. Attention enhances PFC ERP mediated by non-ACh basal forebrain neurons. Basal forebrain is center of ACh-ergin neurons that project throughout cortex, important for to-down attention, cortical activity/plasticity, and arousal states. Yet, the majority of basal forebrain output is GABAergic, and to a somewhat lesser degree, glutamatergic. (These two combined make up 2/3 of the output.) These latter neurons innervate cortical interneurons, perhaps disinhibiting cortex. How do we identify these non-ACh-ergic output? ACh phenotype of arousal was used to isolate neurons in rats. Once these neurons were isolated, rats were given a go/no-go task to see if these non-ACh-ergic neurons were involved in attention. Multimodal, rewarding and non-rewarding, and motor- and passivityincentivizing cues were use; the only consistent property was salient. These neurons fired in response to the salient stimuli, and only after the conditioning. (Extinction eliminates this firing.) Next, they sought to relate the firing to performance. All-or-none burst firing, typical of the neuron population, predicted successful tone detection. This pattern is consistent in all neurons that show the bursting response. Next experiments involved ERPs in humans, involving an oddball task, a commonly us4ed attention task in humans. Cortical ERP bursting should be correlated with BF activity. Target stimuli were seen to recruit great bursting, and it was correlated nicely with cortical firing. Even baseline, non-target firing was correlated in both regions. This test was performed multimodally. A good analogy for the BF activity in top-down attention is as a signal amplifier for those stimuli which are salient. E. Procyk, Bron (Fr); PFC in dynamic behavior. Relation between aCC and lateral PFC. ACC is involved with encoding & adapting action values to bias decisions and detecting/evaluating action outcomes/feedbacks; lPFC is involved in implementing cognitive control. ACC and LPFC are active (monitoring/controlling?) during adaptive behaviors. A test was devised in which a monkey had to search for a target, repeat the behavior directed at the correct target, and then transit to searching for the next correct target after a signal to change. Average region activity was recorded with electric-recording plates on the ROIs. In the ACC, incorrect and the initial correct responses were higher than repeated correct responses, and the incorrect condition produced a higher peak and greater latency than the first correct response. In the LPFC, the incorrect responses produced greater activation than either of the correct responses. LPF was more involved in searching. Signal to chance resulted in above-baseline activity before the feedback in ACC and LPFC. ACC incorrect responses shows activity before any PFC activity. ACC, therefore, was the immediate region to react to the change; the LPFC acted mostly after the signals indicated a need to change response. MaryAnn Noonan, Oxford; mOFC in relative reward comparisons in the Macaque. It is more challenging to select options when their rewards are more similar than when they’re more difference. It’s even more difficult when there are multiple options. mOFC damage influences how much the third option influences the choice in options. Four monkeys were lesioned in the mOFC. This experiment will be compared to monkeys damaged in the lOFC from previous experiments. The experiments involved selecting from three stimuli on a screen, each of which having varying probabilities for reward. The second-best option (V2) had its probability for reward vary between trials. When only given two options, and when the difference is large, the monkeys had no problem figuring out which to choose, same when the difference was moderate. When it was small, it was a struggle to determine. lOFC lesioned monkeys had an opposite trend, performing worst when the differences were greatest. After, in a difference experiment, reward schedules fluctuated continually throughout. (I’m not sure how this experiment works; it’s not clear to me and went by too quickly. It involves too much abstract math and statistics too quickly for me to understand it.) It was shown (somehow) that including a third option made post-op animals choose the best option less frequently, unlike pre-op. (Look up the “independence axiom.” Controls follow this principle; others do not.) Andrew Bell, probability. How does prior probability bias choice? Inferior temporal cortex represents end stage of higher order visual processing.How/if do priors (prior probabilities) influence IT? Is IT merely sensory? If so, we would only expect its role to be limited to one stimulus. Monkeys were presented cues (with noise), then they had to saccade to the previously displayed stimulus. Single neurons were selected, and compared for conditions when cues were 100%, 75%, and 25% faces. The response during correct responses was proportionate to the probability of facial appearance. When the cues were 100% faces and the monkey chose incorrectly, though, the signal was reduced. When the cue was 50% faces, the same trend was present but reduced. (Possible confounds are using faces, given the STS’s role; also, it’s unsure how much this extends to other modalities.)