Heidi Castle

Causal manipulation of feed-forward and recurrent processing differentially affects measures of consciousness

Neuroscience of Consciousness, 2020

It has been theorized that cortical feed-forward and recurrent neural activity support unconsciou... more It has been theorized that cortical feed-forward and recurrent neural activity support unconscious and conscious cognitive processes, respectively. Here we causally tested this proposition by applying event-related transcranial magnetic stimulation (TMS) at early and late times relative to visual stimuli, together with a pulse designed to suppress conscious detection. Consistent with pre-registered hypotheses, early TMS affected residual, reportedly 'unseen' capacity. However, conscious perception also appeared critically dependent upon feed-forward processing to a greater extent than the later recurrent phase. Additional exploratory analyses suggested that these early effects dissociated from top-down criterion measures, which were most affected by later TMS. These findings are inconsistent with a simple dichotomy where feed-forward and recurrent processes correspond to unconscious and conscious mechanisms. Instead, different components of awareness may correspond to different phases of cortical dynamics in which initial processing is broadly perceptual whereas later recurrent processing might relate to decision to report.

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<title>Tactile displays for enhanced performance and safety</title>

Proceedings of SPIE, Sep 15, 2004

Platform performance and safety are dependent on operator situational awareness. This is traditio... more Platform performance and safety are dependent on operator situational awareness. This is traditionally achieved via visual and audio displays but an intuitive alternative is the tactile display. A familiar tactile display is the vibrating alert function of the mobile telephone but more complex tactile display applications have been demonstrated in a number of scenarios, including fixed and rotary wing aircraft, high-speed boats, diving, and assisting the visually impaired. The major applications include orientation, navigation, and communication. A recent NATO Research & Technology Organisation symposium on spatial disorientation (La Coruna, Spain, 2002) stated that; 'The most important advance of recent years with the potential to combat spatial disorientation has been the use of tactile stimuli to give information on spatial orientation'.

The workload implications of haptic displays in multi-display environments such as the cockpit: Dual-task interference of within-sense haptic inputs (tactile/proprioceptive) and between-sense inputs (tactile/proprioceptive/auditory/visual)

CASTLE, HEIDI. The Workload Implications of Haptic Displays in Multi-Display Environments such as... more CASTLE, HEIDI. The Workload Implications of Haptic Displays in Multi-Display Environments such as the Cockpit: Dual-Task Interference of Within-Sense Haptic Inputs (Tactile/ Proprioceptive) and Between-Sense Inputs (Tactile/ Proprioceptive/ Auditory/ Visual). (Under the direction of D Harris &J Hetherington). Visual workload demand within the cockpit is reaching saturation, whereas the haptic sense (proprioceptive and tactile sensation) is relatively untapped, despite studies suggesting the benefits of haptic displays.

The role of occipital feed forward and recurrent processing in relation to consciousness

The workload implications of haptic displays in multi-display environments such as the cockpit: Dual-task interference of within-sense haptic inputs (tactile/proprioceptive) and between-sense inputs (tactile/proprioceptive/auditory/visual)

CASTLE, HEIDI. The Workload Implications of Haptic Displays in Multi-Display Environments such as... more CASTLE, HEIDI. The Workload Implications of Haptic Displays in Multi-Display Environments such as the Cockpit: Dual-Task Interference of Within-Sense Haptic Inputs (Tactile/ Proprioceptive) and Between-Sense Inputs (Tactile/ Proprioceptive/ Auditory/ Visual). (Under the direction of D Harris &J Hetherington). Visual workload demand within the cockpit is reaching saturation, whereas the haptic sense (proprioceptive and tactile sensation) is relatively untapped, despite studies suggesting the benefits of haptic displays.

OP-NCON200015 1..13

It has been theorized that cortical feed-forward and recurrent neural activity support unconsciou... more It has been theorized that cortical feed-forward and recurrent neural activity support unconscious and conscious cognitive processes, respectively. Here we causally tested this proposition by applying event-related transcranial magnetic stimulation (TMS) at early and late times relative to visual stimuli, together with a pulse designed to suppress conscious detection. Consistent with pre-registered hypotheses, early TMS affected residual, reportedly ‘unseen’ capacity. However, conscious perception also appeared critically dependent upon feed-forward processing to a greater extent than the later recurrent phase. Additional exploratory analyses suggested that these early effects dissociated from top-down criterion measures, which were most affected by later TMS. These findings are inconsistent with a simple dichotomy where feed-forward and recurrent processes correspond to unconscious and conscious mechanisms. Instead, different components of awareness may correspond to different phas...

Causal manipulation of feed-forward and recurrent processing differentially affects measures of consciousness

It has been theorised that cortical feed-forward and recurrent neural activity support unconsciou... more It has been theorised that cortical feed-forward and recurrent neural activity support unconscious and conscious cognitive processes, respectively. Here we causally tested this by applying event-related transcranial magnetic stimulation (TMS) at early and late times relative to visual stimuli, within the context of TMS-induced blindsight where consciousness and unconscious perception dissociate. Consistent with pre-registered hypotheses, early TMS affected residual, reportedly “unseen” capacity. However, conscious perception also appeared critically dependent upon feed-forward processing to a greater extent than the later recurrent phase. Additional exploratory analyses suggested that these early effects dissociated from top-down criterion measures, which were most affected by later TMS. These findings are inconsistent with a simple dichotomy where feed-forward and recurrent processes correspond to unconscious and conscious mechanisms. Instead, different aspects of awareness may cor...

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<title>Tactile displays for enhanced performance and safety</title>

Defense, Security, and Cockpit Displays, 2004

Platform performance and safety are dependent on operator situational awareness. This is traditio... more Platform performance and safety are dependent on operator situational awareness. This is traditionally achieved via visual and audio displays but an intuitive alternative is the tactile display. A familiar tactile display is the vibrating alert function of the mobile telephone but more complex tactile display applications have been demonstrated in a number of scenarios, including fixed and rotary wing aircraft, high-speed boats, diving, and assisting the visually impaired. The major applications include orientation, navigation, and communication. A recent NATO Research & Technology Organisation symposium on spatial disorientation (La Coruna, Spain, 2002) stated that; 'The most important advance of recent years with the potential to combat spatial disorientation has been the use of tactile stimuli to give information on spatial orientation'.

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