Delayed Non-Matching-to-Sample
Overview
Delayed non-matching-to-sample (DNMTS) is a recognition memory paradigm in which the subject must choose the novel (non-matching) stimulus after a delay period. The subject is presented with a sample, then after a delay must select the stimulus that differs from the sample. This novelty-preference rule engages different cognitive processes than DMTS — it relies on recognition memory and the ability to detect familiarity, rather than maintaining a representation for later comparison.
DNMTS is particularly sensitive to medial temporal lobe damage, especially perirhinal cortex lesions, which impair object recognition memory. The paradigm has been central to the development of animal models of amnesia and has been extensively used to study the effects of hippocampal and thalamic lesions on recognition memory.
ConductMaze automates DNMTS with the same flexible stimulus and delay parameters as DMTS, but with the non-match rule. The software tracks both delay-dependent accuracy curves and response biases, supports titrating-delay procedures that adjust delay duration based on performance, and generates recognition memory indices.
Trial Flow
Sample Presentation
Sample stimulus presented
Sample Response
Subject responds to sample to initiate delay
Delay Period
Configurable retention interval
Comparison Presented
Sample and novel stimulus presented simultaneously
Choice Response
Subject must select the NOVEL (non-matching) stimulus
Outcome
Non-match = reinforcer; match = timeout
ITI
Inter-trial interval before next trial
Parameters
| Parameter | Type | Default | Description |
|---|---|---|---|
| Delay Durations | enum | 0,4,8,16,32 | Set of delay intervals in seconds |
| Trials per Delay | integer | 12 | Number of trials at each delay per session |
| Sample Duration | seconds | 5 | Duration of sample stimulus presentation |
| Limited Hold | seconds | 10 | Maximum time to make comparison choice |
| ITI Duration | seconds | 10 | Inter-trial interval |
| Titrating Delay | boolean | false | Adjust delay based on performance (increase after correct, decrease after incorrect) |
| Stimulus Modality | enum | Spatial | Stimulus type (spatial, visual, object) |
Metrics
| Metric | Unit | Description |
|---|---|---|
| Percent Correct | % | Accuracy at each delay interval |
| Forgetting Curve Slope | %/s | Rate of accuracy decline with increasing delay |
| Choice Latency | seconds | Mean time from comparison onset to choice |
| Titrated Delay | seconds | Adjusted delay achieved when using titrating procedure |
| Omissions | count | Trials with no response within limited hold |
| Perseverative Errors | count | Consecutive errors to the previously correct stimulus |
Sample Data
| Delay_s | Trials | Correct | Pct_Correct | Mean_Latency_s | Omissions |
|---|
Representative data for illustration purposes. Actual values will vary by species, strain, and experimental conditions.
Applications
- 1Recognition memory — perirhinal-dependent object recognition in rodents and primates
- 2Amnesia modeling — characterizing memory deficits from hippocampal or thalamic lesions
- 3Aging and dementia — delay-dependent recognition memory decline in aged animals
- 4Cholinergic pharmacology — scopolamine-induced deficits as a positive control for pro-cognitive drugs
- 5Titrating-delay procedure — individualized memory capacity assessment for sensitive within-subject designs
Related Protocols
Compatible Products
Ready to Automate Your Behavioral Protocols?
Contact us for a demo and pricing information.
