Changes in biometric data in handwriting of person who is under the influence of alcohol

Studies have shown that alcohol affects the central nervous system, causing changes such as an increase in letter size, distortion of shapes, imbalance in word and letter spacing, and a decrease in legibility. The main objective of this study is to examine the effects of alcohol consumption on the biometric data and static appearance of handwriting samples taken in a digital environment. In this context, the mean and standard deviation values of the data before and after alcohol consumption were calculated for the entire sample group, as well as for subgroups separated by blood alcohol level and gender. The Wilcoxon Signed-Rank test was used to perform a statistical analysis of the biometric data before and after alcohol consumption. In addition, the Mann Whitney U test was used to analyze whether there was a significant difference between the data obtained from the handwriting of female and male volunteers before and after alcohol consumption. In addition to all these analyses performed with biometric data, static examinations were also included in the study. When the biometric data of the entire sample group was examined, including the handwriting of individuals with blood alcohol levels below and above 80 mg/100 dl, and further grouped by gender, it was determined that the most informative biometric data regarding alcohol consumption were "Total Writing Time in Contact" and "Writing Length While in Contact." It is thought that this is due to problems caused by the effects of alcohol on the cerebellum, which is responsible for motor coordination, leading to cerebellar disorders and resulting in flattening of the writing, increased letter height, deterioration in writing quality, and increased spacing between letters. Although it is generally known in the literature that the negative effects of alcohol on motor performance begin at blood alcohol levels above 50 mg/100 ml and deteriorate significantly at 80 mg/100 dl , this study found that, especially at an alcohol level of 80 mg/100 dl, the deterioration in handwriting is not solely dependent on blood alcohol levels but can also vary depending on individual factors such as tolerance level and gender.