Consciousness
Saturday, October 01st, 2011 [17:20 - 19:20]
PS_2.001 - Psychophysical measures of emotional consciousness: threshold-based approach
Szczepanowski, R.
Wroclaw Faculty of Psychology, Warsaw School of Social Sciences and Humanities, Grunwaldzka Street 98, 50-357 Wroclaw, Poland
The study justified the intuition that emotional consciousness could occur as an effect of interactions between discrete cognitive processes of availability and accessibility at a global threshold. The relationships between both cognitive processes were investigated by engaging the participants in backward masking tasks with subliminally presented emotional faces. Psychophysical measures of the interactions between both cognitive processes were taken with a threshold model by Krantz. In first experiment, the exclusivity relationship was examined which presumed that there is the threshold beyond which emotional stimulation is strong enough for the participant to gain access to consciousness, but no longer available. There was clear evidence that both cognitive processes were mutually exclusive when emotional target exposure increased. In the second experiment, the independence interaction was tested implicating that both cognitive processes act in concert in producing conscious performance, and therefore there are some proportions of emotional items that are consciously available and consciously accessed. As compare with the “exclusivity” condition, psychophysical measures indicated stronger evidence that emotional consciousness followed the independence interaction. Overall, the study showed that subjects’ performance could be driven by cognitive processes of threshold-like nature, and their interactions could lead to plausible effects in producing conscious behavior during masking.
PS_2.002 - Expertise effects on the access to consciousness
Vermeiren, A. 1 , Beyens, U. 1 , Fu, Q. 2 & Cleeremans, A. 1
1 Université Libre de Bruxelles
2 Chinese Academy of Sciences
Expertise in a certain domain can increase the visibility for stimuli from that domain. For example, car experts will recognize a car better when they see a flash of a car on the street. Here, we study whether expertise can influence not only the objective identification performance, but also the subjective feeling of having seen a stimulus. Chinese and European participants were asked to identify chinese and maya signs which were presented only for a short amount of time (16 ms). Furthermore, they were asked to rate their awareness of the stimuli. It was found that both identification and awareness were higher for the chinese signs than for the maya signs when testing Chinese participants, while the opposite was true for the European participants. This effect started already at very short SOA’s (stimulus-onset-asynchrony) between the stimulus and the post-mask. This suggests that early on in the visual processing stream, feedback loops render previous knowledge (expertise) available, allowing identification performance and subjective awareness of visual objects to increase more rapidly.
PS_2.003 - Is consciousness graded or dichotomous?
Windey, B. 1 , Gevers, W. 2 & Cleeremans, A. 1
1 CO3. ULB. Brussels, Belgium
2 Unescog. ULB. Brussels, Belgium
This study aims to shed light on an ongoing debate in the visual awareness literature: is the transition from unconscious to conscious processing graded or dichotomous? The Recurrent Processing Hypothesis assumes a graded transition (longer presentation durations lead to gradually enhanced visibility). The Global Workspace Theory assumes an all-or-none transition (stimuli remain unconscious until the duration is sufficient to generate sudden clear experiences). Here we intend to unify the two theories and their supporting evidence, by taking the so far overlooked factor of the “level of processing” of stimuli into account. Participants performed a task on low-level stimuli (categorizing colored patches as red or blue) or on high-level stimuli (categorizing numbers as smaller or larger than 5). Presentation duration of the postmasked stimuli was varied parametrically. As expected, the psychophysical detection curve for the low-level stimuli showed a graded pattern, whereas the curve for the high-level stimuli showed a dichotomous pattern. In the next experiment we present the same stimuli (colored numbers) in both conditions, to match both conditions more closely. We hypothesize that for low-level stimuli, access to a more graded local workspace is sufficient to become conscious, whereas high-level stimuli require access to an all-or-none global workspace.
PS_2.004 - Your unconscious knows your name
Pohl, C. , Pfister, R. , Kiesel, A. & Kunde, W.
University of Wuerzburg
The own name constitutes a unique part of conscious awareness, but it is also unique for the unconscious mind? To answer this question, we employed a subliminal priming experiment. Participants decided as fast as possible whether a name or a non-word was presented as target. Unbeknown to them, already before the target, a masked prime stimulus was briefly presented. The prime was either one of the targets, a non-word, the own name of the participant, or the name of a yoked participant. When one's own name was presented as prime, responding to a name target was substantially facilitated, whereas presenting the name of the other participant had the same effect as presenting a non-word prime. Thus, we show that - in contrast to any other name - one's own name has the power to bias a person's actions, even when the presence of the own name is unexpected and unconscious. The brain identifies and processes its name even in the absence of conscious awareness.
PS_2.005 - Modeling sensorimotor habits with neuro-robotics: a reappraisal of the habit concept in psychology
Barandiaran, X. & Di Paolo, E. .
Department of Logic and Philosophy of Science, UPV-EHU University of the Basque Country, Donostia - San Sebastian, Spain
Recent trends in cognitive science have seriously undermined the notion of representation (symbolic or sub-symbolic) as a building block for theory construction and modeling in cognitive science (Stewart et al. 2011). The current lack of a clear theoretical building block for dynamical, embodied and situated cognitive approaches calls for a re-appraisal of the notion of habit as developed by early pragmatists (James, Pierce and Dewey) and continental psychologists and philosophers (Köhler, Goldstein, Merleau-Ponty). Whereas contemporary computational neuroscience and machine learning approaches (Daw et al. 2005) still sustain a behaviorist (S-R probabilistic association) conception of habit, we propose a richer notion by modeling habits as self-sustaining behavioural neurodynamic patterns where activity-dependent plasticity shows an extended temporal structure. We illustrate this point with some work on evolutionary robotics, implementing a combination of Hebbian and homeostatic plasticity (as recently supported by different neurobiological studies--Turrigiano 2000, 2007). In our robotic models, this mechanism is capable to generate sensorimotor development, reinforcement learning, spontaneous habit formation and re-habituation to sensorimotor disruptions (Di Paolo 2000, Barandiaran and Di Paolo 2010). We conclude that a richer notion of habit can significantly contribute to the foundations of cognitive science, opening up the possibility to model poorly understood psychological phenomena.