Effects of Intravenously Given Barbiturate and Diazepam on Eye Motor Performance in Man

Holzman

Matthysse

et al. 1993

Schizophrenia Bulletin

276

196

Eye tracking dysfunction (ETD) has been found in large numbers of schizophrenia patients and their first-degree relatives. Because of the many replications of the central findings, ETD has been proposed as a useful way of expanding the schizophrenia phenotype in genetic studies. We critically review the literature on ETD with respect to issues of measurement and the search for quantitative indices of ETD; syndrome and familial specificity of ETD for schizophrenia; statistical, interpretive, and methodological considerations in the use of mixture analysis; the association of ETD with clinically and psychometrically defined schizotypy; and the questions of trait stability and medication effects.

Section: Further Methodological Considerationsmentioning

confidence: 99%

Eye Tracking Dysfunction and Schizophrenia: A Critical Perspective

Holzman

Matthysse

et al. 1993

Schizophrenia Bulletin

276

196

“…The low prevalence of Type I tracking and the absence of group differences in the rate of AS make it unlikely that AS account for the elevated prevalence of ETD in certain groups. The square-wave tracking described by Shagass et al (1976; see their figure 3) and the "large amplitude nontracking" saccades described by Spohn et al (1988) were probably AS. Average gain calculations that include epochs with AS, in which gain is reduced to or near zero, should not be included in an assessment of the integrity of the pursuit system because the eye is not engaged in pursuit.…”

Section: Precise Quantitative Measuresmentioning

confidence: 89%

“…Although modern psychotropic drugs were not a factor in the early eye tracking studies (Diefendorf and Dodge 1908; Couch and Fox 1934; White 1938), barbiturates were customarily used then to control agitation. This class of drugs impairs pursuit (Schalen et al 1988), and their use may have affected the results reported by Couch and Fox (1934) and by White (1938).…”

Section: Specificity Of Etdmentioning

confidence: 99%

Eye Tracking and Schizophrenia: A Selective Review

Holzman

Matthysse

et al. 1994

Schizophrenia Bulletin

158

“…Impaired pursuit was found during periods of clinical exacerbation, corresponding to periods of barbiturate treatment, whereas pursuit normalized during periods of remission, corresponding to barbiturate discontinuation. Only later were barbiturates discovered to impair pursuit (Rashbass and Russell 1961; Schalen et al 1988), suggesting that what appeared at the time to be an association between clinical state and pursuit performance was actually a drug-induced epiphenomenon. …”

mentioning

confidence: 99%

Eye Tracking Dysfunction in Schizophrenia: Characterization and Pathophysiology

Current Topics in Behavioral Neurosciences

Sereno

Gooding

et al. 2010

124

Eye tracking dysfunction (ETD) is one of the most widely replicated behavioral deficits in schizophrenia and is over-represented in clinically unaffected first-degree relatives of schizophrenia patients. Here, we provide an overview of research relevant to the characterization and pathophysiology of this impairment. Deficits are most robust in the maintenance phase of pursuit, particularly during the tracking of predictable target movement. Impairments are also found in pursuit initiation and correlate with performance on tests of motion processing, implicating early sensory processing of motion signals. Taken together, the evidence suggests that ETD involves higher-order structures, including the frontal eye fields, which adjust the gain of the pursuit response to visual and anticipated target movement, as well as early parts of the pursuit pathway, including motion areas (the middle temporal area and the adjacent medial superior temporal area). Broader application of localizing behavioral paradigms in patient and family studies would be advantageous for refining the eye tracking phenotype for genetic studies.