The effect of the speaker's confmnatory question on understandability of verbal explanation

Previous studies have shown that confirmatory questions enhance the understandability of an explanation. Examples include asking a degree of understanding of the listener and current state of the description target in verbal explanation. In the current study, we examined the effect of two types of confirmatory question by tbe speaker on tbe degree of understanding of the listener. The experimenter verbally explained to participants how to draw a geometric figore. We manipulated tbe types of explanation: (a) tbe speaker aaks a degree of understanding of the listener dwing explanation, (b) the speaker asks a current state of the description target during explanation, and (c) the speaker simply repeats the explanation. As a result, tbe highest understandability score was attained when tbe explanation was repeated. Accuracy scores of the drawing were high in all three situations; we therefore conclude that conimnatory questions are not effective in every situation of verbal explanation. Repetition of the explanation is sufficient to increase the listener's understanding if the content of the description is simple

The novel de novo mutation of KIF1A gene as the cause for Spastic paraplegia 30 in a Japanese case

Spastic paraplegia 30 is a recently established autosomal recessive disease characterized by a complex form of spastic paraplegia associated with neuropathy. Homozygous mutations of KIF1A reportedly lead to hereditary spastic paraplegia or hereditary sensory and autonomic neuropathy type 2 (HSAN2), whereas heterozygous mutations can cause nonsyndromic and syndromic intellectual disability (MRD9). Here we report the case of a 37-year-old female who presented with gait disturbance complicated with moyamoya disease. Results: The patient exhibited hypotonia during infancy, after which intellectual disability, epileptic fits, spastic paraplegia, and cerebellar atrophy occurred. Genetic analysis revealed a novel de novo mutation (c.254C > A, p.A85D) in the motor domain of KIF1A. Keywords: KIF1A, Spastic paraplegia 30: SPG30, Moyamoya disease, Gene, HSAN2, Mental retardation, Autosomal dominant 9, MRD