Ad hoc reviewer for more than 50 international journals. Editor of Consciousness and Cognition (Elsevier / Academic Press). Information about Talis Bachmann's research can be found in bachmannlab.com website (e.g., use Google for search).
Ambiguous figures (aka bistable, multistable, or reversible images) have fascinated scientists as... more Ambiguous figures (aka bistable, multistable, or reversible images) have fascinated scientists as well as laypersons for centuries. It may be surprising indeed how one and the same physical depiction can be experienced in perceptual awareness in cardinally different ways. In the most well-known examples of such illusions of multistability, the phenomenal change relates just to visual organization. Much less common are perceptions of alternating emotional content in the ambiguous visual image. Here, I introduce one such example.
We present a theoretical view of the cellular foundations for network-level processes involved in... more We present a theoretical view of the cellular foundations for network-level processes involved in producing our conscious experience. Inputs to apical synapses in layer 1 of a large subset of neocortical cells are summed at an integration zone near the top of their apical trunk. These inputs come from diverse sources and provide a context within which the transmission of information abstracted from sensory input to their basal and perisomatic synapses can be amplified when relevant. We argue that apical amplification enables conscious perceptual experience and makes it more flexible, and thus more adaptive, by being sensitive to context. Apical amplification provides a possible mechanism for recurrent processing theory that avoids strong loops. It makes the broadcasting hypothesized by global neuronal workspace theories feasible while preserving the distinct contributions of the individual cells receiving the broadcast. It also provides mechanisms that contribute to the holistic asp...
Predictions about the world can guide our perception and action, but they can also misguide us. W... more Predictions about the world can guide our perception and action, but they can also misguide us. We developed novel dual-task setups where the participants are occupied by a primary task and are from time to time queried about the phenomenal contents of the auxiliary task. We show that “hallucinating” the presence of an actually absent stimulus is not an exception, but a common phenomenon (more than 90% of participants experienced illusory objects at least once). Additionally, in experiment 1 we found a negative correlation between the amount of illusory perceptions and the Autism Spectrum Quotient score. People who scored higher on the questionnaire, were less likely to experience illusory objects. Finally, we observed no effect of spatial attention on expectation-based illusory presence of an object. More generally our results demonstrate that expectations misguide perception when attention is diverted to another task.
When about half a century ago masking research emerged as one of the hot topics in psychophysics,... more When about half a century ago masking research emerged as one of the hot topics in psychophysics, cognitive psychology and psychophysiology, Bruce Bridgeman was among the leaders in this domain. His studies and papers on masking must not be overlooked also today. This article brings to the readers a brief review of Bridgeman's contributions to the field and directly related research from other laboratories, with an eye on the implications for consciousness studies.
The present study investigated individual differences in how much subjects rely on prior informat... more The present study investigated individual differences in how much subjects rely on prior information, such as expectations or knowledge, when faced with perceptual ambiguity. The behavioural performance of forty-four participants was measured on four different visual paradigms (Mooney face recognition, illusory contours, blur detection and representational momentum) in which priors have been shown to affect perception. In addition, questionnaires were used to measure autistic and schizotypal traits in the non-clinical population. We hypothesized that someone who in the face of ambiguous or noisy perceptual input relies heavily on priors, would exhibit this tendency across a variety of tasks. This general pattern would then be reflected in high pairwise correlations between the behavioural measures and an emerging common factor. On the contrary, our results imply that there is no single factor that explains the individual differences present in the aforementioned tasks, as further ev...
Ambiguous figures (aka bistable, multistable, or reversible images) have fascinated scientists as... more Ambiguous figures (aka bistable, multistable, or reversible images) have fascinated scientists as well as laypersons for centuries. It may be surprising indeed how one and the same physical depiction can be experienced in perceptual awareness in cardinally different ways. In the most well-known examples of such illusions of multistability, the phenomenal change relates just to visual organization. Much less common are perceptions of alternating emotional content in the ambiguous visual image. Here, I introduce one such example.
We present a theoretical view of the cellular foundations for network-level processes involved in... more We present a theoretical view of the cellular foundations for network-level processes involved in producing our conscious experience. Inputs to apical synapses in layer 1 of a large subset of neocortical cells are summed at an integration zone near the top of their apical trunk. These inputs come from diverse sources and provide a context within which the transmission of information abstracted from sensory input to their basal and perisomatic synapses can be amplified when relevant. We argue that apical amplification enables conscious perceptual experience and makes it more flexible, and thus more adaptive, by being sensitive to context. Apical amplification provides a possible mechanism for recurrent processing theory that avoids strong loops. It makes the broadcasting hypothesized by global neuronal workspace theories feasible while preserving the distinct contributions of the individual cells receiving the broadcast. It also provides mechanisms that contribute to the holistic asp...
Predictions about the world can guide our perception and action, but they can also misguide us. W... more Predictions about the world can guide our perception and action, but they can also misguide us. We developed novel dual-task setups where the participants are occupied by a primary task and are from time to time queried about the phenomenal contents of the auxiliary task. We show that “hallucinating” the presence of an actually absent stimulus is not an exception, but a common phenomenon (more than 90% of participants experienced illusory objects at least once). Additionally, in experiment 1 we found a negative correlation between the amount of illusory perceptions and the Autism Spectrum Quotient score. People who scored higher on the questionnaire, were less likely to experience illusory objects. Finally, we observed no effect of spatial attention on expectation-based illusory presence of an object. More generally our results demonstrate that expectations misguide perception when attention is diverted to another task.
When about half a century ago masking research emerged as one of the hot topics in psychophysics,... more When about half a century ago masking research emerged as one of the hot topics in psychophysics, cognitive psychology and psychophysiology, Bruce Bridgeman was among the leaders in this domain. His studies and papers on masking must not be overlooked also today. This article brings to the readers a brief review of Bridgeman's contributions to the field and directly related research from other laboratories, with an eye on the implications for consciousness studies.
The present study investigated individual differences in how much subjects rely on prior informat... more The present study investigated individual differences in how much subjects rely on prior information, such as expectations or knowledge, when faced with perceptual ambiguity. The behavioural performance of forty-four participants was measured on four different visual paradigms (Mooney face recognition, illusory contours, blur detection and representational momentum) in which priors have been shown to affect perception. In addition, questionnaires were used to measure autistic and schizotypal traits in the non-clinical population. We hypothesized that someone who in the face of ambiguous or noisy perceptual input relies heavily on priors, would exhibit this tendency across a variety of tasks. This general pattern would then be reflected in high pairwise correlations between the behavioural measures and an emerging common factor. On the contrary, our results imply that there is no single factor that explains the individual differences present in the aforementioned tasks, as further ev...
ADVANCES IN CONSCIOUSNESS RESEARCH ADVANCES IN CONSCIOUSNESS RESEARCH provides a forum for schola... more ADVANCES IN CONSCIOUSNESS RESEARCH ADVANCES IN CONSCIOUSNESS RESEARCH provides a forum for scholars from different scientific disciplines and fields of knowledge who study conscious-ness in its mulrifaceted aspects. Thus the Series will include (but not be ...
Juhend teadusliku uurimistöö tegemiseks: teadusliku uurimuse olemus, kirjutamise, viitamise ja vo... more Juhend teadusliku uurimistöö tegemiseks: teadusliku uurimuse olemus, kirjutamise, viitamise ja vormistamise reeglid.
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