There is general agreement that the IPS is involved in processing numerical magnitude information [ 16] as well as in processes of place-value integration in multi-digit number processing [ 5, 17, 30].
Second, a left lateralized predominance within the IPS for the processing of magnitude irrelevant parity information for auditorily presented number words, as compared to a right lateralization for number magnitude, corroborates the notion that parity information may be represented in some kind of verbally mediated store for simple arithmetical properties.
The Gini index for the joint spectro-temporal sparsity in each channel is computed by processing the magnitude spectrogram of that channel and is plotted in Fig. 5 d, along with the joint spectro-spatio-temporal sparsity for all K·R·T coefficients.
This network comprised the horizontal segment of the IPS (hIPS), which has repeatedly been identified to be vitally involved in processing number magnitude (for reviews [ 16, 31]).
Finally, in the third and last step, the activation patterns indicating task specific processing in magnitude comparison and parity judgements were directly compared to investigate possible differences between number comparison and parity judgement.
Critically, in order to conclude that any effect, if found, was related to holistic processing, the magnitude of this effect must be higher for the intact eyes than for the shifted eyes stimuli set.
Previously, processing number magnitude (for a review see [ 16]) as well as place-value integration were both associated specifically with activation of the intraparietal sulcus (IPS; see [ 17, 18], see also [ 19] for a distinction between the neural correlates of processing single- and two-digit numbers).
On a neuro-functional level the (horizontal segment of the) intraparietal sulcus (hIPS) has repeatedly been identified to be vitally involved when it comes to processing number magnitude information of different formats (symbolic digits: e.g., [ 10, 11]; dot patterns: e.g., [ 12, 13], see [ 14] for common activations of the IPS for symbolic and non-symbolic quantity).
Human parietal cortex appears also to be specialized for this purpose because parietal cortex participates in mental rotation task [28] and in the processing of magnitudes of temporal discrepancy and of numerical differences [29] [31].
In conclusion, there is evidence for a deficient recruitment of neural resources in children with DD when processing analog magnitudes of numbers.
