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Mizrachi, N.

Publications and source records attributed to Mizrachi, N..

2 recordsLinked to original sources

The dynamics of episodic recall

The mechanistic understanding of memory recall, a process long known to be influenced by environmental context, has posed a persistent challenge to neuron-centric models. In this study, we approached recall by shifting the focus from internal neuronal representations to brain-environment interactions, employing precise tracking of gaze dynamics within a well-controlled virtual reality (VR) setting. We found that each verbal report of recalled event was consistently preceded by a gradual process of brain-environment coupling: fixational pauses became progressively longer, while gaze direction slowly converged on a specific spatial location associated with the memorized object--a recall-specific location (RSL). Upon the initiation of the verbal report, gaze rapidly diverged from the RSL. Chunked verbal reports were associated with convergence onto shared or spatially clustered RSLs. Moreover, when recall occurred in the same spatial context as encoding, participants recalled objects in the order they were encountered and RSLs were more correlated with gaze locations during encoding. These findings reveal a direct mechanistic dependence of memory recall on the environment and support the view that the environment is not merely a context for memory, but an integral component of the memory itself.

neuroscience↗

Active palpation underlying shape perception is shaped by physiological thresholds and experience.

Hand movements are essential for tactile perception of objects. However, why different individuals converge on specific movement patterns is not yet clear. Focusing on planar shape perception, we tracked the hands of 11 participants while they practiced shape recognition. Our results show that planar shape perception is mediated by contour-following movements, either tangential to the contour or spatially-oscillating perpendicular to it, and by scanning movements, crossing between distant parts of the shapes contour. Both strategies exhibited non-uniform coverage of the shapes contours. We found that choice of strategy during the first experimental session was strongly correlated with two idiosyncratic parameters: participants with lower tactile resolution tended to move faster; and faster-adapting participants tended to employ oscillatory movements more often. In addition, practicing on isolated geometric features increased the tendency to use the contour-following strategy. These results provide insights into the processes of strategy selection in tactile perception. SIGNIFICANCE STATMENTHand movements are integral components of tactile perception. Yet, the specific motion strategies used to perceive specific objects and features, and their dependence on physiological features and on experience, are understudied. Focusing on planar shape perception and using high-speed hand tracking we show that human participants employ two basic palpation strategies: Contour-following and scanning. We further show that the strategy chosen by each participant and its kinematics depend strongly on the participants physiological thresholds - indicative of spatial resolution and temporal adaptation - and on their perceptual experience.

neuroscience↗