Psychology
Central Nervous System [CNS] influence by alcohol has been studies extensively due to its inhibitory effects. Such studies are crucial in inferring how alcohol impairs the performance of an individual. Alcohol causes a dose-related depression of the CNS until a person loses consciousness. Alcohol affects both cognitive and visual functioning. Visual functioning can be related to the effect of alcohol on critical flicker fusion frequency [CFF]. CFF refers to the frequency of light for which an individual observes a continuous response. Alcohol is capable of lowering CFF in a physiological manner similar to that in dark adaptation.
This review seeks to explore this phenomenon of lowering of CFF by alcohol. In achieving this, the review examines two similar articles. This analysis of these articles follows particular criteria that aim at inferring the implications of alcohol on CFF. The two articles articulate through a similar issue. However, the method of study used and the tests undertaken in either of the articles are also different. The primary argument in the two articles involves the determination of the question of whether alcohol affects vision.
Background information
Alcohol in this context refers to a psychoactive substance with dose-related effect on the CNS. According to Matson (2014), alcohol interacts with GABA receptor complex to produce various effects on CNS depending on its bioavailability. Initially, alcohol produces excitation of the CNS. Continued intake of alcohol results in high Blood Alcohol Concentration (BAC) that causes depression of the cortical and CNS activity. Alcohol consumption results in altered experiences such as atypical neural activity. Alcohol has been shown to cause impairment of some visual abilities. One such ability involves visual processing at low-level stimuli.
Summary
The first article is “Differential Effects of Alcohol on Rod and Cone Temporal Processing” by Pauline Pearson and Brian Timney. This article focuses on the impact of alcohol on CFF. Pearson and Timney (1999) speculate that alcohol causes a decline of CFF. The authors determine the influence of alcohol on CFF by determining the response during photopic and low mesopic. In determining the relationship between these two entities, the authors measured CFF when under the stimuli of alcohol of a concentration of 0.06 percent in six study samples of even gender. The independent samples in their study were retinal positions and alcohol concentration. The dependent variable was the obtained CFF. Analysis of these variables involved the use of Students t-test. The t-test helped to determine whether the change of CFF with changing retinal location and alcohol concentration were due to chance or not.
Upon conduction of the experiment, Pearson and Tomney (1999) found that there was consistent decline in CFF at a particular BAC for photopic stimuli. This decrease was aggregately uniform for various retinal positions. Under mesopic luminance, similar results were indicated. However, under mesopic stimuli, CFF reduction was only for retinal positions that were more central. These findings are crucial in showing that alcohol is capable of affecting vision. In this case, the results reveal that alcohol affects vision selectively and depending on the type of stimuli. The results imply that cones are highly affected by alcohol compared to rods whose functioning is less affected.
The second article is “How alcohol intake affects visual temporal processing” by Marina Kunchulia, Karin S. Pilz and Michael H. Herzog. These authors seek to determine the how alcohol affects spatiotemporal processing. The authors explore the general effects of alcohol on visual functions of which temporal processing is one. In achieving this, the authors use an inhomogeneous mask test to infer alcohol effect on temporal processing. The authors determined stimulus onset asynchronies (SOA). The independent variable was vernier duration, BAC and grating elements while the dependent variable was the SOA.
The authors use a Student t test to determine the relationship between the various variables. Kunchulia, Pilz and Herzog (2012) found that there were increased thresholds of vernier duration due masking. They conclude that alcohol does not affect nor lower visual stimuli and processing respectively. Kunchulia, Pilz and Herzog’s article has extended their results by trying to discern how alcohol influences temporal processing and consider alcohol amount in their results. Pearson and Timney’s article only state the results that alcohol affects temporal processing. They fail to explain how such influence of alcohol on temporal processing occurs. The authors do not validate or nullify a relationship between threshold and CFF. Therefore, I would seek to determine how these two aspects relate to each other.
References
Kunchulia, M., Pilz, K. S., & Herzog, M. H. (2012). How alcohol intake affects visual temporal processing. Vision research, 66, 11-16.
Matson, S. J. (2014). The effects of alcohol on different classes of motion perception. Electronic Thesis and Dissertation Repository, Paper 2632.
Pearson, P. & Timney, B. (1999). Differential effects of alcohol on rod and cone temporal processing. Journal of studies on alcohol, 60(6), 879-883.
