Soft haptic sensation increases the expectation in the social context but not in the non-social context

Previous studies have proposed that holding soft objects can increase expectations to be included in a Cyberball task. The present study investigated whether effects of holding soft objects on expectations are restricted to social contexts or can appear in non-social contexts. Sixty-six participants performed a social or non-social ball task, both modified versions of the Cyberball task. In the social ball task, participants were told that they would play a ball-tossing game with computer-generated players. In the non-social ball task, participants were told that they would take part in a judgement task. During the task, participants held either soft or hard cushions, and their electroencephalographic signals were recorded to evaluate the contingent negative variation (CNV), which is considered to reflect expectation and anticipation of an imperative stimulus. The results showed that participants who performed the social ball task exhibited larger late CNV when they held the soft cushion compared to when they held the hard cushion, whereas participants who performed the non-social ball task exhibited no such difference. The results indicate that holding soft objects increases expectations to be included only in social contexts.