TITLE:
The Effects of Hand Preference on Attention
AUTHORS:
Sergio L. Schmidt, Eunice do Nascimento Simões, Guilherme J. Schmidt, Ana Lucia Novais Carvalho, Ana Lucia Novais Carvalho
KEYWORDS:
ADHD; Handedness; Laterality
JOURNAL NAME:
Psychology,
Vol.4 No.10A,
October
24,
2013
ABSTRACT:
Handedness is associated with cerebral
hemispheric differences. Normal patterns of brain asymmetries are needed for
the neural processing of attention. In order to identify ADHD (Attention
Deficit Hyperactive Disorder) children, the use of checklists allows a greater
level of accuracy. Here, we will review our data on this subject. Our first
study investigated the psychometric properties of a scale developed to assess attention
disorders. Our second study investigated the relationship between handedness
and attention disorders using the factors derived from the scale. Our third
study included the use of a continuous visual test of attention (CVAT) and
examined the relationship between handedness and CVAT variables. For the first
and second study, 239 students were included. From this sample, 42 students
were selected to participate in the third study. Forty-five teachers rated the
children. Four factors were extracted: hyperactivity/impulsivity (explained
variance = 36.3%); inattention (11.4%); social isolation (5.2%) and self-confidence
(explained variance = 3.3%). Sixty-eight children were included in the ADHD
group. We found a higher number of consistent left-handers in the ADHD group as
compared to the normal group and a significant effect of handedness on factor hyperactivity/impulsivity.
This indicated that left-handers showed greater problems in the
hyperactivity-impulsivity domain as compared to right-handers. Considering the
data derived from CVAT, a significant handedness effect was found only for the
variable commission errors. Left-handers with attention problems showed the
greatest number of errors and normal dextrals the lowest number of errors.
Normal left-handers made significantly more errors than normal dextrals. Commission
error is a parameter that is commonly viewed as a measure of impulsivity. Our
data show that hyperactivity/impulsivity is related to handedness, because
left-handers present more problems in impulsive behavior than right-handers and
suggest that consistent left-handed subjects show greater probability to
develop ADHD as compared to right-handed subjects.