Long-term effects of cannabis on eye movement control in reading

Huestegge, Lynn; Kunert, Hanns Jürgen; Radach, Ralph

doi:10.1007/s00213-009-1769-z

Cited by 34 publications

(39 citation statements)

References 35 publications

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“…Many recent studies additionally revealed rather long-lasting effects on basic oculomotor control, especially after chronic use. [12] Even so, it is still unknown to what extent these deficits play a role in everyday tasks that strongly rely on an efficient saccade system, such as reading.…”

Section: Effect Of Cannabis On Cognitionmentioning

confidence: 99%

“…[20] There may be relatively subtle performance deficits on the level of basic oculomotor control that scale up as task complexity and cognitive demands increase. [12] Cognitive dysfunction associated with long-term or heavy cannabis use is similar in many respects to the cognitive endophenotypes that have been proposed as vulnerability markers of schizophrenia. [2122] Some studies have reported complete recovery of impairments after 4 weeks of abstinence, whereas other studies describe persisting cognitive deficits, especially in the domains of attention, memory and executive functions[1923] or only partial recovery of cognitive impairments in abstinent users.…”

Section: Evidence For Dose Dependencymentioning

confidence: 99%

“…[52] The results indicate that relatively subtle performance deficits on the level of basicoculomotor control increase as task complexity and cognitive demands increase. [12] Delta-9-THC might differentially affect schizophrenia patients relative to control subjects. The enhanced sensitivity to the cognitive effects of delta-9-THC warrants further study into whether brain cannabinoid receptor dysfunction contributes to the pathophysiology of the cognitive deficits associated with schizophrenia.…”

Section: Cannabis and Psychosismentioning

confidence: 99%

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Cannabis use and cognitive dysfunction

Shrivastava

Johnston

Tsuang

2011

Indian J Psychiatry

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Section: Effect Of Cannabis On Cognitionmentioning

confidence: 99%

Section: Evidence For Dose Dependencymentioning

confidence: 99%

Section: Cannabis and Psychosismentioning

confidence: 99%

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Cannabis use and cognitive dysfunction

Shrivastava

Johnston

Tsuang

2011

Indian J Psychiatry

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“…17 Bartholomew et al 18 caution however, that young people may often not even notice the memory losses. Further, it also impacts visual motor skills, 18,19 general cognition and thinking processes 20 and can induce psychotic symptoms such as hallucinations and delusions, again, much like what is found in individuals with schizophrenia. 17 Paradoxically, cannabis is the most commonly used drug in individuals who suffer with schizophrenia.…”

Section: Cognitionmentioning

confidence: 87%

Neuropsychiatric Effects of Marijuana

Wadieh¹

2017

MOJAMT

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Background: Cannabis (Marijuana) is one of the most widely used illicit drugs around the world. In the United States, it is the most commonly-used illicit drug. While there have been increasing numbers of arguments about legalizing marijuana primarily for its medicinal and recreational use, there remain concerns about its impact on the brain: neuropsychiatric problems, in particular, from its chronic use. Purpose & Method:To highlight recent knowledge, understanding and research of marijuana, its potency, mechanism of action, effects on psychomotor and cognitive performance and other neuropsychiatric function are explored; paying particular attention to the long term effects of Marijuana usage. Marijuana interacts with endogenous cannabinoid (CB) systems in the body. Actions on specific brain receptors are reflected in CB dose-related impairments of psychomotor performance. Further effects relating to psychosis, memory problems, and depression, are also experienced; primarily as a result of cortex degeneration. Conclusion:Marijuana significantly impacts the brain, specifically, the brain's structure, function and connectivity. Although marijuana use is linked to many neurological and psychiatric effects from long term use, it is often perceived in society as harmless

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“…Eighty sentences taken from the work of Huestegge et al (2010) were presented one by one. Text was presented in regular Arial font size 16 pt corresponding to 0.24°at the given viewing distance of 60 cm.…”

Section: Methodsmentioning

confidence: 99%

Binocular Coordination in Reading When Changing Background Brightness

Köpsel

Huckauf²

2017

Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences.

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INTRODUCTIONWhen we look, we fixate on an object of interest with both eyes. The process of aligning both focus points is referred to as binocular coordination, the result of this process is termed vergence. That is, a vergence point is defined as the position where both lines of sight meet. Understanding the alignment of both lines of sight is important also for the understanding of binocular vision, that is, the motor coordination of the eyes as well as the perceptual coordination like, for example, in image fusion. In visual tasks, vergence points are expected to occur where an image is depicted. Therefore, when presenting images on a screen, the fixation location of both eyes is measured on the screen. The resulting difference between fixation locations of both eyes is referred to as fixation disparity. That is, fixation disparity is the difference between the two lines of sight at a given distance, which informs about the spatial accuracy of aligning both lines of sight.Binocular coordination is performed also in seemingly two-dimensional tasks like, for example, in reading. This raises the question of whether two eyes are better than one, as Radach and Heller (1999) put it. With regard to fixation disparity in reading, there are contradictory results. Liversedge et al. (2006) reported that about half of the fixations accompanying reading are unaligned. The authors characterised these fixations as crossed or uncrossed, depending on their disparity: fixations were counted as crossed when the right eye fixated more than one character left of the left eye, and as uncrossed when the right eye fixated more than one character right of the left eye. Expressed as vergence, crossed fixations were described as a vergence point spatially in front of the screen, and uncrossed fixations as a vergence point behind the screen. Liversedge et al. (2006) found more uncrossed fixation disparities than crossed ones, that is, a mean vergence point behind the screen.In contrast, a dominance of crossed fixations and hence, vergence points, which are typically in front of the screen, was reported by Nuthmann and Kliegl (2009). With regard to binocular coordination, one might wonder how image fusion can take place on the basis of such huge amounts of not aligned fixations. In order to understand binocular visual functioning, it is therefore important to distinguish systematic variations of fixation alignments from random variability.There were already various reasons suggested as potentially being responsible for the differences in the findings of Nuthmann and Kliegl (2009) as compared to : differing eye-trackers, calibration procedures, viewing distances and also letter sizes. The former used a chin rest, the latter a bite bar, and participants had to read in different languages (German vs. English). These differences and several more (e.g., glasses, contact lenses, eye colour, PROCEEDINGS OF THE LATVIAN ACADEMY OF SCIENCES. Section B, Vol. 71 (2017)

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Long-term effects of cannabis on eye movement control in reading

Abstract: The results indicate that relatively subtle performance deficits on the level of basic oculomotor control scale up as task complexity and cognitive demands increase.

Cited by 34 publications

References 35 publications

Cannabis use and cognitive dysfunction

Cannabis use and cognitive dysfunction

Neuropsychiatric Effects of Marijuana

Binocular Coordination in Reading When Changing Background Brightness

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