Stoycheva Polina, Tiippana Kaisa
a Department of Psychology and Logopedics, Faculty of Medicine , University of Helsinki , Helsinki , Finland.
Laterality. 2018 Nov;23(6):684-704. doi: 10.1080/1357650X.2018.1450881. Epub 2018 Mar 14.
The brain's left hemisphere often displays advantages in processing verbal information, while the right hemisphere favours processing non-verbal information. In the haptic domain due to contra-lateral innervations, this functional lateralization is reflected in a hand advantage during certain functions. Findings regarding the hand-hemisphere advantage for haptic information remain contradictory, however. This study addressed these laterality effects and their interaction with memory retention times in the haptic modality. Participants performed haptic discrimination of letters, geometric shapes and nonsense shapes at memory retention times of 5, 15 and 30 s with the left and right hand separately, and we measured the discriminability index d'. The d' values were significantly higher for letters and geometric shapes than for nonsense shapes. This might result from dual coding (naming + spatial) or/and from a low stimulus complexity. There was no stimulus-specific laterality effect. However, we found a time-dependent laterality effect, which revealed that the performance of the left hand-right hemisphere was sustained up to 15 s, while the performance of the right-hand-left hemisphere decreased progressively throughout all retention times. This suggests that haptic memory traces are more robust to decay when they are processed by the left hand-right hemisphere.
大脑左半球在处理语言信息时通常具有优势，而右半球则更倾向于处理非语言信息。在触觉领域，由于对侧神经支配，这种功能侧化在某些功能中表现为手部优势。然而，关于触觉信息的手-半球优势的研究结果仍然相互矛盾。本研究探讨了这些偏侧性效应及其与触觉模态中记忆保持时间的相互作用。参与者分别用左手和右手在5秒、15秒和30秒的记忆保持时间内对字母、几何形状和无意义形状进行触觉辨别，我们测量了辨别指数d'。字母和几何形状的d'值显著高于无意义形状。这可能是由于双重编码（命名+空间）或/和刺激复杂性较低所致。没有刺激特异性的偏侧性效应。然而，我们发现了一种时间依赖性的偏侧性效应，即左手-右半球的表现可持续到15秒，而右手-左半球的表现在所有保持时间内逐渐下降。这表明，当触觉记忆痕迹由左手-右半球处理时，它们对衰退的抵抗力更强。
