A common reference frame for movement plans in the posterior parietal cortex

By systematically manipulating head position relative to the body and eye position relative to the head, previous studies have shown that vestibular tuning curves of neurons in the ventral intraparietal (VIP) area remain invariant when expressed in body-/world-centered coordinates. However, body orientation relative to the world was not manipulated; thus, an egocentric, body-centered representation could not be distinguished from an allocentric, world-centered reference frame. We manipulated the orientation of the body relative to the world such that we could distinguish whether vestibular heading signals in VIP are organized in body- or world-centered reference frames. We found a hybrid representation, depending on gaze direction. When gaze remained fixed relative to the body, the vestibular heading tuning of VIP neurons shifted systematically with body orientation, indicating an egocentric, body-centered reference frame. In contrast, when gaze remained fixed relative to the world, this representation changed to be intermediate between body- and world-centered. We conclude that the neural representation of heading in posterior parietal cortex is flexible, depending on gaze and possibly attentional demands.

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Posterior parietal cortex mediates encoding processes in change blindness

PsycEXTRA Dataset ◽

10.1037/e520562012-977 ◽

2009 ◽

Author(s):

Philip Tseng ◽

Cassidy Sterling ◽

Adam Cooper ◽

Bruce Bridgeman ◽

Neil G. Muggleton ◽

...

Keyword(s):

Parietal Cortex ◽

Posterior Parietal Cortex ◽

Change Blindness ◽

Posterior Parietal

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The Grasp Cell Hypothesis: Near-miss effect points to common neurological machinery in posterior parietal cortex for controllable objects and concepts

10.31234/osf.io/4awrz ◽

2018 ◽

Author(s):

Imogen M Kruse

Keyword(s):

Parietal Cortex ◽

Posterior Parietal Cortex ◽

Near Miss ◽

Illusion Of Control ◽

Gambling Behaviour ◽

Drug Seeking ◽

Spatial Influence ◽

Reward Probability ◽

Posterior Parietal ◽

Action Value

The near-miss effect in gambling behaviour occurs when an outcome which is close to a win outcome invigorates gambling behaviour notwithstanding lack of associated reward. In this paper I postulate that the processing of concepts which are deemed controllable is rooted in neurological machinery located in the posterior parietal cortex specialised for the processing of objects which are immediately actionable or controllable because they are within reach. I theorise that the use of a common machinery facilitates spatial influence on the perception of concepts such that the win outcome which is 'almost complete' is perceived as being 'almost within reach'. The perceived realisability of the win increases subjective reward probability and the associated expected action value which impacts decision-making and behaviour. This novel hypothesis is the first to offer a neurological model which can comprehensively explain many empirical findings associated with the near-miss effect as well as other gambling phenomena such as the ‘illusion of control’. Furthermore, when extended to other compulsive behaviours such as drug addiction, the model can offer an explanation for continued drug-seeking following devaluation and for the increase in cravings in response to perceived opportunity to self-administer, neither of which can be explained by simple reinforcement models alone. This paper therefore provides an innovative and unifying perspective for the study and treatment of behavioural and substance addictions.

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