Extrageniculate Contributions to Reflex Visual Orienting in Normal Humans: A Temporal Hemifield Advantage

Abstract

Evidence is presented that the phylogenetically older retin-otectal pathway contributes to reflex orienting of visual attention in normal human subjects. The study exploited a lateralized neuroanatomic arrangement of retinotectal pathways that distinguishes them from those of the geniculostriate system; namely, more direct projections to the colliculus from the temporal hemifield. Subjects were tested under monocular viewing conditions and responded to the detection of a peripheral signal by making either a saccade to it or a choice reaction time manual keypress. Attention was summoned by noninformative peripheral precues, and the benefits and costs of attention were calculated relative to a central precue condition. Both the benefits and costs of orienting attention were greater when attention was summoned by signals in the temporal hemifield. This temporal hemifield advantage was present for both saccade and manual responses. These findings converge with observations in patients with occipital and midbrain lesions to show that the phylogenetically older retinotectal pathway retains an important role in controlling visually guided behavior; and they demonstrate the usefulness of temporal-nasal hemifield asymmetries as a marker for investigating extrageniculate vision in humans.

Gaze Perception Triggers Reflexive Visuospatial Orienting

“…These similarities are noteworthy because the effects of peripheral cues have been attributed by numerous authors to reflexive, subcortical neural pathways involving the superior colliculus (e.g. Rafal et al, 1991;Rafal & Henik, 1994;Spence & Driver, 1994, 1997. Such neuroanatomical conclusions have been based on a wide range of data, including studies of patient groups with subcortical damage (see Rafal & Henik, 1994), anatomical manipulations in healthy people (see Rafal et al, 1991) and analogies with animal studies (Spence & Driver, 1997;Stein & Meredith, 1993).…”

“…Rafal et al, 1991;Rafal & Henik, 1994;Spence & Driver, 1994, 1997. Such neuroanatomical conclusions have been based on a wide range of data, including studies of patient groups with subcortical damage (see Rafal & Henik, 1994), anatomical manipulations in healthy people (see Rafal et al, 1991) and analogies with animal studies (Spence & Driver, 1997;Stein & Meredith, 1993). It should be of considerable interest to study the neural basis for the orienting in response to seen gaze which we have identified here.…”

“…Jonides, 1981;Klein et al, 1992;Muller & Rabbitt, 1989;Posner & Cohen, 1984;Spence & Driver, 1994, 1997, and it is strongly suspected that different neural substrates are involved (e.g. Rafal, Henik, & Smith, 1991). Many authors associate exogenous orienting with subcortical structures, in particular the superior colliculus (e.g.…”

“…Many authors associate exogenous orienting with subcortical structures, in particular the superior colliculus (e.g. Rafal et al, 1991;Spence & Driver, 1997;Stein & Meredith, 1993).…”

Attentional Effects of Counterpredictive Gaze and Arrow Cues.

“…There is considerable evidence in the attentional literature indicating that reflexive orienting to a sudden onset at a peripheral location and volitional orienting to an expected target location occur by way of different brain pathways. Reflexive orienting to a sudden onset in the periphery is thought to involve the superior colliculus (SC), working in concert with parietal cortex (Rafal, Henik, & Smith, 1991;Rafal, Posner, Friedman, Inhoff, & Bernstein, 1988), whereas volitional orienting to an expected target location is thought to involve frontal and parietal areas (Corbetta, Miezin, Shulman, & Petersen, 1993;Posner, 1995;Posner & Raichle, 1994). It seems likely, however, that reflexive orienting triggered by gaze direction does not occur by way of either of these pathways.…”