Long-Term Memory for Haptically Explored Objects: Fidelity, Durability, Incidental Encoding, and Cross-Modal Transfer

Abstract

The question of how many of our perceptual experiences are stored in long-term memory has received considerable attention. The present study examined long-term memory for haptic experiences. Blindfolded participants haptically explored 168 everyday objects (e.g., a pen) for 10 s each. In a blindfolded memory test, they indicated which of two objects from the same basic-level category (e.g., two different pens) had been touched before. As shown in Experiment 1 ( N = 26), memory was nearly perfect when tested immediately after exploration (94%) and still high when tested after 1 week (85%). As shown in Experiment 2 ( N = 43), when participants explored the objects without the intention to memorize them, memory in a 1-week delayed surprise test was still high (79%), even when assessed with a cross-modal visual memory test (73%). These results indicate that detailed, durable, long-term memory representations are stored as a natural product of haptic perception.

Long-Lasting Verbatim Memory for the Words of Books After a Single Reading Without Any Learning Intention

“…In particular, the present findings demonstrate that this holds even true for the reading of whole book chapters, and that not only the syntax is remembered but also the exact words that were written at specific positions in the book. The finding of successful memory retrieval despite absent subjective memory awareness is in line with findings demonstrating the phenomenon of recognition without awareness in verbal (Craik et al, 2015), visual (Voss et al, 2008), and haptic memory (Hutmacher and Kuhbandner, 2018), supporting speculations that there is a perceptual long-term memory system that operates below awareness (Johnson, 1983). In particular, the finding that performance did not decrease across 1 week supports findings that perceptual long-term-memory representations show little forgetting (Hutmacher and Kuhbandner, 2020) and may even be permanently stored (Mitchell, 2006).…”

“…The finding that performance can be above chance in n-alternative forced choice recognition test despite participants claiming that they are guessing without having any phenomenal memory experience is supported by several studies (e.g., Voss et al, 2008;Craik et al, 2015;Hutmacher and Kuhbandner, 2018). Based on such findings, it has been assumed that there is a third subtype of memory beyond the awareness-dependent (explicit) subtypes of recollection and familiarity: an unconscious (implicit) subtype of memory, which is not accompanied by a phenomenal (i.e., conscious) experience of remembering, termed "recognition without awareness" or "implicit recognition" (for a review, see Voss et al, 2012).…”

Does Touching Real Objects Affect Learning?

“…Within this framework of embodiment, haptic exploration may contribute to offline cognition and learning in several ways. Firstly, it adds an additional layer of sensorimotor input, contributing to an enriched mental representation that can be easily accessed and reinstantiated (Hutmacher and Kuhbandner 2018;Lacey and Sathian 2014). Secondly, reactivation of stored efferent activities may be fed into forward models which allow the cognitive system to emulate actions in an offline manner (Glenberg et al 2013;Grush 2004).…”

“…Recent studies demonstrate that haptic experiences of objects lead to detailed and durable long-term memory representations, indicating that touch constitutes an important sensory channel of environmental information on its own (Hutmacher and Kuhbandner 2018). Additionally, processing in working memory integrates haptic experiences with information from other sensory channels.…”

Understanding the self of people with dementia

“…Nevertheless, understanding the complexity of the self of people with dementia can help to counterbalance our bias towards the rational and intellectual understanding of who we are. Humans are not only storytellers; humans are also beings with an extremely rich and embodied inner perceptual world (for recent empirical studies with healthy subjects, see, e.g., [12,13]). This insight has a number of important implications for engaging with people with dementia.…”