Continuous sensory-motor transformation and their electrophysiological signatures

Szul, Maciej 2019. Continuous sensory-motor transformation and their electrophysiological signatures. PhD Thesis, Cardiff University. Item availability restricted.

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Abstract

Perceptual decisions require efficient transformation of sensory information to motor responses. Most laboratory-based research on decision-making consid- ered discrete and over-simplified actions. This thesis focused on human perfor- mance and electrophysiological signatures of continuous actions in response to decisions from three aspects. First, a systematic comparison between joystick movements and key presses showed that behavioural performance and under- lying cognitive processes are not affected by response modality, establishing the validity and consistency of using joystick trajectories to measure decision responses. Second, a behavioural paradigm was developed to integrate continu- ous circular joystick movements with perceptual decisions of coherent motion. The signal-to-noise ratio of sensory inputs has been shown to affect the ac- curacy and response time of ongoing actions, but its influence on movement speed diminished after substantial training. Multivariate pattern analysis on magnetoecephalography (MEG) data recorded during the experiment identi- fied stable information representations that sensitive to the quality of sensory information as well as the direction of periodic kinematics of circular move- ments. Furthermore, pattern information of complex actions was observed prior to movement onset, indicating the encoding of abstract preparatory ac- tion plans. Third, this thesis investigated the MEG signatures of circular joystick movements initiated via voluntary choices, instead of external sensory inputs. In a novel oddball paradigm, voluntarily choosing a continuous action built up an expectation of the statistical regularity of subsequent sensory in- puts. Violating that expectation via incongruent sensory information resulted in significant multivariate representation in MEG activity of the mismatch event. Overall results presented in this thesis highlighted how ongoing actions can be influenced by, and impact on, the continuous processing of sensory inputs in the human brain

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Psychology
Subjects:	B Philosophy. Psychology. Religion > BF Psychology
Date of First Compliant Deposit:	4 September 2020
Date of Acceptance:	13 August 2020
Last Modified:	25 May 2021 01:26
URI:	https://orca.cardiff.ac.uk/id/eprint/134645

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