Colour Terms Affect Detection of Colour and Colour-Associated Objects Suppressed from Visual Awareness

Abstract

The idea that language can affect how we see the world continues to create controversy. A potentially important study in this field has shown that when an object is suppressed from visual awareness using continuous flash suppression (a form of binocular rivalry), detection of the object is differently affected by a preceding word prime depending on whether the prime matches or does not match the object. This may suggest that language can affect early stages of vision. We replicated this paradigm and further investigated whether colour terms likewise influence the detection of colours or colour-associated object images suppressed from visual awareness by continuous flash suppression. This method presents rapidly changing visual noise to one eye while the target stimulus is presented to the other. It has been shown to delay conscious perception of a target for up to several minutes. In Experiment 1 we presented greyscale photos of objects. They were either preceded by a congruent object label, an incongruent label, or white noise. Detection sensitivity (d') and hit rates were significantly poorer for suppressed objects preceded by an incongruent label compared to a congruent label or noise. In Experiment 2, targets were coloured discs preceded by a colour term. Detection sensitivity was significantly worse for suppressed colour patches preceded by an incongruent colour term as compared to a congruent term or white noise. In Experiment 3 targets were suppressed greyscale object images preceded by an auditory presentation of a colour term. On congruent trials the colour term matched the object's stereotypical colour and on incongruent trials the colour term mismatched. Detection sensitivity was significantly poorer on incongruent trials than congruent trials. Overall, these findings suggest that colour terms affect awareness of coloured stimuli and colour- associated objects, and provide new evidence for language-perception interaction in the brain.

Fig 1. Experiment 1 task procedure for object-present trials.

An audio cue (either an object label or white noise) was presented over headphones before the dominant eye was presented with flashing (10 Hz) square random noise patterns. On half the trials the audio cue was an object label and on the other half the audio cue was white noise. Targets were greyscale photos presented to the other eye.

Fig 2. Results from Experiment 1 (object targets preceded by an object label or noise).

Three measures of performance for detecting greyscale objects suppressed from visual awareness through CFS: (A) Reaction time, (B) Hit rate, and (C) Detection sensitivity (d’). The objects were preceded by one of three types of audio cue: Con. (congruent object label; green), Incon. (incongruent object label; red), or Noise (grey). Error bars show ± 1 SEM. ** p < .01; *** p < .001.

Fig 3. Results from Experiment 2 (colour targets preceded by a colour term or noise).

Three measures of performance for detecting circular colour patches suppressed from visual awareness through CFS: (A) Reaction time, (B) Hit rate, and (C) Detection sensitivity (d’). The colour patches were preceded by one of three types of audio cue: Con. (congruent colour term; green), Incon. (incongruent colour term; red), or Noise (grey). Error bars show ± 1 SEM. ** p < .01; *** p < .001.

Fig 4. Results from Experiment 3 (object targets preceded by a colour term or noise).

Three measures of performance for detecting greyscale objects suppressed from visual awareness using CFS: (A) Reaction time, (B) Hit rate, and (C) Detection sensitivity (d’). The objects were each associated with a single colour (e.g., a banana is associated with yellow) and were preceded by one of three types of audio cue: Con. (congruent colour term; green), Incon. (incongruent colour term; red), or Noise (grey). Error bars show ± 1 SEM. * p < .05.