Analysis of Self and Retrieval Generated Priming in Human Recognition Memory

In this report, I have documented the development of an eye-tracking procedure able to distinguish between the influence of Self (SGP) and Retrieval Generated Priming (RGP), effects postulated by the Wagner’s Sometimes Opponent Process (SOP) model. The procedures of Relative Recency (RR), Object in Place (OIP) and Object in Context (OIC) map onto the two postulated mechanisms and so the primary goal was to exhibit both effects in the human eye-tracking procedure. In the RR procedure, participants have demonstrated to look at stimuli which were pre- exposed earlier in the past when compared with a more recently presented one. In both OIP and OIC, participants engaged more with stimuli which were presented in either a novel spatial arrangement or accompanied by a novel context. Such effects mirror the SOP-derived predictions and demonstrate the involvement of SGP and RGP in the human recognition memory. A key difference between the SGP- and RGP-enabled effects is the influence of time. Hence, the model is evaluated regarding such manipulations applied to RR, OIC and OIP procedures. To that extent, the mathematical tenets of SOP were employed to simulate the experimental procedures, whose predicted results were experimentally tested. Overall, both mechanisms were demonstrated, however, their effects were sensitive to a time-dependent decay. Overall, the experiments reported yield support for the associative account of recognition memory. I argue that the SOP offers a parsimonious, computational, and robust model of recognition memory and that the procedures developed for this thesis offer a more sensitive measure than the procedures currently used for that purpose

Analysis of Self and Retrieval Generated Priming in Human Recognition Memory

In this report, I have documented the development of an eye-tracking procedure able to distinguish between the influence of Self (SGP) and Retrieval Generated Priming (RGP), effects postulated by the Wagner’s Sometimes Opponent Process (SOP) model. The procedures of Relative Recency (RR), Object in Place (OIP) and Object in Context (OIC) map onto the two postulated mechanisms and so the primary goal was to exhibit both effects in the human eye-tracking procedure. In the RR procedure, participants have demonstrated to look at stimuli which were pre- exposed earlier in the past when compared with a more recently presented one. In both OIP and OIC, participants engaged more with stimuli which were presented in either a novel spatial arrangement or accompanied by a novel context. Such effects mirror the SOP-derived predictions and demonstrate the involvement of SGP and RGP in the human recognition memory. A key difference between the SGP- and RGP-enabled effects is the influence of time. Hence, the model is evaluated regarding such manipulations applied to RR, OIC and OIP procedures. To that extent, the mathematical tenets of SOP were employed to simulate the experimental procedures, whose predicted results were experimentally tested. Overall, both mechanisms were demonstrated, however, their effects were sensitive to a time-dependent decay. Overall, the experiments reported yield support for the associative account of recognition memory. I argue that the SOP offers a parsimonious, computational, and robust model of recognition memory and that the procedures developed for this thesis offer a more sensitive measure than the procedures currently used for that purpose

An associative analysis of recognition memory: Relative recency effects in an eye-tracking paradigm

We report 2 eye-tracking experiments with human variants of 2 rodent recognition memory tasks, relative recency and object-in-place. In Experiment 1 participants were sequentially exposed to 2 images, A then B, presented on a computer display. When subsequently tested with both images, participants biased looking toward the first-presented image A: the relative recency effect. When contextual stimuli x and y, respectively, accompanied A and B in the exposure phase (xA,yB), the recency effect was greater when y was present at test, than when x was present. In Experiment 2 participants viewed 2 identical presentations of a 4-image array, ABCD, followed by a test with the same array, but in which one of thepairs of stimuli exchanged position (BACD orABDC). Participants looked preferentially at the displaced stimulus pair: the object-in-place effect. Three further conditions replicated Experiment 1’s findings: 2 pairs of images were presented one after the other (AB followed by CD); on a test with AB and CD,relative recency was again evident as preferential looking at AB. Moreover, this effect was greater when the positions of the first-presented A and B were exchanged between exposure and test (BACD), compared with when the positions of second-presented C and D were exchanged (ABDC). The results were interpreted within the theoretical framework of the Sometime Opponent Process model of associative learning (Wagner, 1981)

Action video game training reduces the Simon Effect

Abstract A number of studies have shown that training on action video games improves various aspects of visual cognition including selective attention and inhibitory control. Here, we demonstrate that action video game play can also reduce the Simon Effect, and, hence, may have the potential to improve response selection during the planning and execution of goal-directed action. Non-game-players were randomly assigned to one of four groups; two trained on a first-person shooter game (Call of Duty) on either Microsoft Xbox or Nintendo DS, one trained on a visual training game for Nintendo DS, and a control group who received no training. Response times were used to contrast performance before and after training on a behavioral assay designed to manipulate stimulus-response compatibility (the Simon Task). The results revealed significantly faster response times and a reduced cost of stimulusresponse incompatibility in the groups trained on the first-person-shooter game. No benefit of training was observed in the control group or the group trained on the visual training game. These findings are consistent with previous evidence that action game play elicits plastic changes in the neural circuits that serve attentional control, and suggest training may facilitate goal-directed action by improving players' ability to resolve conflict during response selection and execution

3D DEM simulations of basic geotechnical tests with early detection of shear localization

This paper deals with elementary geotechnical tests: triaxial and direct shear of cohesionless sand using the discrete element method (DEM). The capabilities of the numerical DEM code are shown, with a special focus on the early phenomena appearance in localization zones. The numerical tests were performed in 3D conditions with spherical grains. Contact moments law was introduced due to simulate not perfectly round sand grains. The influence of different physical parameters was studied, e.g. initial density or confining pressure. The sieve curve corresponded to the Karlsruhe sand [1]; however, in some tests, it was linearly scaled. Special attention was laid on the behaviour of the sand grains inside localization, e.g. rotation, porosity, fluctuations, etc. and forces redistribution. Emphasis was given on the pre-failure regime and early localization predictors

3D DEM simulations of basic geotechnical tests with early detection of shear localization

This paper deals with elementary geotechnical tests: triaxial and direct shear of cohesionless sand using the discrete element method (DEM). The capabilities of the numerical DEM code are shown, with a special focus on the early phenomena appearance in localization zones. The numerical tests were performed in 3D conditions with spherical grains. Contact moments law was introduced due to simulate not perfectly round sand grains. The influence of different physical parameters was studied, e.g. initial density or confining pressure. The sieve curve corresponded to the Karlsruhe sand [1]; however, in some tests, it was linearly scaled. Special attention was laid on the behaviour of the sand grains inside localization, e.g. rotation, porosity, fluctuations, etc. and forces redistribution. Emphasis was given on the pre-failure regime and early localization predictors

Dissociation between the neural correlates of conscious face perception and visual attention.

Given the higher chance to recognize attended compared to unattended stimuli, the specific neural correlates of these two processes, attention and awareness, tend to be intermingled in experimental designs. In this study, we dissociated the neural correlates of conscious face perception from the effects of visual attention. To do this, we presented faces at the threshold of awareness and manipulated attention through the use of exogenous prestimulus cues. We show that the N170 component, a scalp EEG marker of face perception, was modulated independently by attention and by awareness. An earlier P1 component was not modulated by either of the two effects and a later P3 component was indicative of awareness but not of attention. These claims are supported by converging evidence from (a) modulations observed in the average evoked potentials, (b) correlations between neural and behavioral data at the single-subject level, and (c) single-trial analyses. Overall, our results show a clear dissociation between the neural substrates of attention and awareness. Based on these results, we argue that conscious face perception is triggered by a boost in face-selective cortical ensembles that can be modulated by, but are still independent from, visual attention

Action video game training reduces the Simon Effect.

A number of studies have shown that training on action video games improves various aspects of visual cognition including selective attention and inhibitory control. Here, we demonstrate that action video game play can also reduce the Simon Effect, and, hence, may have the potential to improve response selection during the planning and execution of goal-directed action. Non-game-players were randomly assigned to one of four groups; two trained on a first-person-shooter game (Call of Duty) on either Microsoft Xbox or Nintendo DS, one trained on a visual training game for Nintendo DS, and a control group who received no training. Response times were used to contrast performance before and after training on a behavioral assay designed to manipulate stimulus-response compatibility (the Simon Task). The results revealed significantly faster response times and a reduced cost of stimulus-response incompatibility in the groups trained on the first-person-shooter game. No benefit of training was observed in the control group or the group trained on the visual training game. These findings are consistent with previous evidence that action game play elicits plastic changes in the neural circuits that serve attentional control, and suggest training may facilitate goal-directed action by improving players' ability to resolve conflict during response selection and execution