No position-specific interference from prior lists in cued recognition: A challenge for position coding (and other) theories of serial memory

Position-specific intrusions of items from prior lists are rare but important phenomena that distinguish broad classes of theory in serial memory. They are uniquely predicted by position coding theories, which assume items on all lists are associated with the same set of codes representing their positions. Activating a position code activates items associated with it in current and prior lists in proportion to their distance from the activated position. Thus, prior list intrusions are most likely to come from the coded position. Alternative "item dependent" theories based on associations between items and contexts built from items have difficulty accounting for the position specificity of prior list intrusions. We tested the position coding account with a position-cued recognition task designed to produce prior list interference. Cuing a position should activate a position code, which should activate items in nearby positions in the current and prior lists. We presented lures from the prior list to test for position-specific activation in response time and error rate; lures from nearby positions should interfere more. We found no evidence for such interference in 10 experiments, falsifying the position coding prediction. We ran two serial recall experiments with the same materials and found position-specific prior list intrusions. These results challenge all theories of serial memory: Position coding theories can explain the prior list intrusions in serial recall and but not the absence of prior list interference in cued recognition. Item dependent theories can explain the absence of prior list interference in cued recognition but cannot explain the occurrence of prior list intrusions in serial recall.

Masked suffix priming and morpheme positional constraints

Although masked stem priming (e.g., dealer-DEAL) is one of the most established effects in visual word identification, it is less clear whether primes and targets sharing a suffix (e.g., kindness-WILDNESS) also yield facilitation. In a new take on this issue, we show that prime nonwords facilitate lexical decisions to target words ending with the same suffix (sheeter-TEACHER) compared to a condition where the critical suffix was substituted by another one (sheetal-TEACHER) or by an unrelated nonmorphological ending (sheetub- TEACHER). We also show that this effect is genuinely morphological, as no priming emerged in noncomplex items with the same orthographic characteristics (sportel-BROTHEL vs. sportic-BROTHEL vs. sportur-BROTHEL). In a further experiment, we took advantage of these results to assess whether suffixes are recognized in a position-specific fashion. Masked suffix priming did not emerge when the relative order of stems and suffixes was reversed in the prime nonwords-ersheet did not yield any time saving in the identification of teacher as compared to either alsheet or obsheet. We take these results to show that -er was not identified as a morpheme in ersheet, thus indicating that suffix identification is position specific. This conclusion is in line with data on interference effects in nonword rejection and strongly constrains theoretical proposals on how complex words are identified. In particular, because these findings were reported in a masked priming paradigm, they suggest that positional constraints operate early, most likely at a prelexical level of morpho-orthographic analysis.